Putin also envisioned a future for war where drones, OSTENSIBLY controlled by artificial intelligence, would fight proxy wars between countries

link to the article

After the participants completed the scrambled-sentence task, they went to another laboratory to participate in what was PURPORTEDLY a second task

link to the book (170th page)

links to the explanations:


it says that purportedly is supposedly; ostensibly is seemingly or apparently

roger that, but


this source conveys some slightly different point in view of previous explanation

  • purportedly

Seemingly: Use when an observable fact is contrary to the truth

  • ostensibly

Supposedly: Use when a fact is rumored to be true

Apparently: Use when the truth of a fact is observable, if one looks

As for me, supposedly and apparently are opposite to each other


This book ostensibly provides the reader with all the information needed to write good prose.

Here the speaker is implying that some other information — the blurb on the book jacket, a review in a newspaper perhaps — has suggested that the book contains the information in question, but that the speaker makes no guarantees on that point and may even be setting up a rebuttal to that contention, following the first sentence with something like "But I found it an utter waste of time."


Oxford dictionary has the word 'purportedly' for 'ostensibly' as a synonym


I wonder what is the difference between 'ostensibly' and 'purportedly'

  • 2
    Replace 'ostensibly with seemingly in the first example and seems to provide in the third example. And purportedly with most likely. I am not sure why you don't reference actual dictionary definitions. ostensibly and purportedly
    – user3169
    Commented Sep 1, 2017 at 23:51
  • The OED lists them as very close synonyms, so I wouldn't worry much about this. (purportedly – "Allegedly, ostensibly.")
    – user3395
    Commented Sep 2, 2017 at 12:27

2 Answers 2


Ostensibly is used to meant that something ought to be true, but either the speaker can't verify its truth, or the speaker suspects it may not be true:

Dr. Jones is, ostensibly, the primary authority on the subject, but nevertheless he often defers to the opinions of other experts.

In the United States the Justice Department is ostensibly independent from the executive, but recent actions by the current president belie its supposed autonomy.

Purportedly is used to indicate something is presented as true, when it is actually false.

Government documents purportedly stated that New Orleans' levies were able to withstand flooding of much greater magnitude than happened after hurricane Katrina in 2005, but the truth was that they were nowhere near enough.

He was said to be the richest man in the country, but, in actuality, his purported wealth existed mostly in his own head.

These are loose synonyms, but purported more strongly indicates deception. For example, in the above example I could change out "supposed" with "purported" to suggest that the government has been actively lying about the Justice Department's independence from the executive branch:

... but recent actions by the current president belie its purported autonomy

  • The third example's use of "purportedly stated" is only correct if you think there is a chance that the government documents did not make the alleged statement. If you are confident that government documents made the alleged statement, then it would be correct to say that "Government documents purported that", because the alleged statement turned out to be incorrect.
    – Jasper
    Commented Sep 2, 2017 at 4:06
  • Per the Constitution, the U.S. Justice Department is not independent from the executive. One of the President's duties is that "he shall take Care that the Laws be faithfully executed". He "may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any subject relating to the Duties of their respective Offices, and he shall have Power to Grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment." Either he, or the Head of the Department (whom he appoints) appoints the department's "inferior Officers".
    – Jasper
    Commented Sep 2, 2017 at 4:16
  • A pre-eminent authority on a subject is likely to be wise enough to value the opinions of other experts. I would be dubious of any purported authority on a subject who could not point out other experts with opinions that he would value.
    – Jasper
    Commented Sep 2, 2017 at 4:20
  • 3
    Describing a claim as "purported" doesn't always mean you're asserting outright that it's false, it just connotes that you hold its factuality under suspicion. The usual use of "purportedly" is for when you're repeating an assertion that someone else has made, but which you yourself do not endorse. The closest synonym is "allegedly," which connotes the same lack of proof for a claim, but less personal suspicion for its veracity.
    – Eikre
    Commented Sep 2, 2017 at 8:13
  • 2
    @Jasper examples on ELL, ostensibly contain valid information, but actually the person writing them could be completely mistaken.
    – Andrew
    Commented Sep 2, 2017 at 21:02

In brief, when something is purported to be X, it is said to be X. When something is ostensibly X, it would appear to be X.

The purported involves a purporter.

The ostensible involves only a perceiver or inferrer or assumer.

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