Random, haphazard, chance, chancy, casual, desultory, hit-or-miss, happy-go-lucky are comparable when they mean having a cause or a character that is determined by accident rather than by design or by method.
What is random comes, goes, occurs, or is done or made without a fixed or clearly defined aim, purpose, or evidence of method or system or direction; the term implies an absence of guidance by a governing mind, eye, or objective.
What is haphazard is done, made, arranged, used, or said without concern or without sufficient concern for its fitness, its effectiveness, or its possible ill effects, and is more or less at the mercy of chance or whim or of natural or logical necessity.
What is described as chance comes or happens to one or is done or made by one without prearrangement or preawareness or without preparation; the term is applicable not only to things but to persons with whom one comes into contact more or less by accident.
What is chancy involves uncertainty and risk because its results, actions, responses, or condition cannot be predicted; the term applies more often to situations and things than to persons.
What is casual (see also ACCIDENTAL ) leaves or seems to leave things to chance, and works, acts, comes, or goes haphazardly or by chance, or without method or deliberation or indication of intent or purpose; the term often also suggests offhandedness or lightness or spontaneity or lack of definiteness in terms or intention.
What is desultory is not governed by method or system but jumps or skips erratically from one thing to another; the term may imply additionally such consequences as irregular or inconsistent performance or lack of continuity or plan or persistence.
What is hit-or-miss is so haphazard in its character or operation as to be or appear so wholly lacking in plan, aim, system, or care that one is indifferent as to how it turns out or as to what pattern or arrangement it makes.
A person is happy-go-lucky who leaves everything to chance or who accepts with happiness or easy indifference whatever comes; a thing is happy-go-lucky that is governed by such a disposition.