The confusion here is the ambiguity and multiple usages for that particular word. There are many words like this in English, due to its inherent ambiguity.
To be explicit, the definition of the word "fix" is as follows:
- fasten (something) securely in a particular place or position. (Most likely, this is a shortening of the word "affix").
Example: "fix the clamp on a rail"
Synonyms: fasten, attach, affix, secure.
- direct one's eyes, attention, or mind steadily or unwaveringly toward.
Example: "I fixed my attention on the tower"
- mend; repair. (the particular case you're referring to)
Example: "you should fix that shelf"
Synonyms: repair, mend, put right, put to rights, get working, restore (to working order)
- do the necessary work to improve or adapt something, i.e., "we want to fix up the house before we sell it".
- make arrangements for (something); organize, i.e., "he's sent her on ahead to fix things up". Synonyms: provide, supply, furnish
- (informal) restore order or tidiness to (something, especially one's hair, clothes, or makeup), i.e., "Laura was fixing her hair". Synonyms: arrange, put in order, adjust
- (informal) prepare or arrange for the provision of (food or drink). i.e., "they were fixing him breakfast". Synonyms: prepare, cook, make, get
- (informal) arrange for someone to have something; provide someone with something. i.e., "I'll fix you up with a room" Synonyms: provide, supply, furnish
- (informal) arrange for someone to meet or go out with someone in order to help them establish a romantic relationship
- (dialect) be intending or planning to do something, i.e., "you're fixing to get into trouble"
- decide or settle on (a specific price, date, course of action, etc.)
Example: "no date has yet been fixed for a hearing"
Synonyms: decide on, select, choose, resolve on
- discover the exact location of (something) by using radar or visual bearings or astronomical observation, i.e., "he fixed his position"
- settle the form of (a language)
- assign or determine (a person's liability or responsibility) for legal purpose. i.e., "there are no facts that fix the defendant with liability"
- make (something) permanent or static in nature.
Example: "the rate of interest is fixed for the life of the loan"
- make (a dye, photographic image, or drawing) permanent. i.e., "chemicals are used to fix the dye" Synonyms: make permanent, make fast, set
- (biology) preserve or stabilize (a specimen) with a chemical substance prior to microscopy or other examination. i.e., "specimens were fixed in buffered formalin"
- (of a plant or microorganism) assimilate (nitrogen or carbon dioxide) by forming a nongaseous compound. i.e., "lupines fix gaseous nitrogen in their root nodules"
- (informal) influence the outcome of (something, especially a race, contest, or election) by illegal or underhanded means.
Example: "the foundation denies fixing races"
Synonyms: rig, arrange fraudulently
- put (an enemy or rival) out of action, especially by killing them. i.e. "don't you tell nobody, or I'll fix you good!". Synonyms: get one's revenge on, avenge oneself on, get even with, get back at, take reprisals against, punish, deal with; sort someone out
- (informal) take an injection of a narcotic drug
- castrate or spay (an animal); neuter
Example: "I just got my cat fixed."
Synonyms: castrate, neuter, geld, spay, desex, sterlize
- (informal) a difficult or awkward situation from which it is hard to extricate oneself; a predicament.
Example: "how on earth did you get into such a fix?"
Synonyms: predicament, plight, difficulty, awkward situation, corner, tight spot.
- (informal) a dose of a narcotic drug to which one is addicted.
Example: "he hadn't had his fix"
Synonyms: dose, hit
- a thing or activity that gives a person a feeling of euphoria or pleasure and that it is difficult to do without. i.e., "that rush of adrenaline that is the fix of the professional skydiver"
- a measure taken to resolve a problem or correct a mistake; a solution or remedy
Example: "representatives trying to find cheap fixes to meet their obligations
Synonyms: solution, answer, resolution, way out, remedy, cure, placebo
- a position determined by visual or radio bearings or astronomical observations
- (informal) a dishonest or underhanded arrangement.
Example: "obviously, his appointment was a fix"
Synonyms: fraud, swindle, trick, charade, sham