According to the ancients, words derived from the basic units, by taking roots and suffixes, can be learnt using the rules of grammar.
The second is through analogy, where we use a known concept to describe an unknown concept. Thi builds on words whose meanings we already know via other methods. Interestingly though, one might infer other characteristics (those not intended) of the known object and associate an unknown object with that, and this is dependent on how detailed the analogy is. If to describe a kangaroo, someone said it was like a rabbit, then that would lead to ambiguity - what about a rabbit is similar? However, mentioning large rabbit implies that the kangaroo is similar in shape and form.
The third is lexicon, the more obvious way of finding meaning. It is a basic list of meaningful units in a language. I believe this method is deeply intertwined with the others. We learn the lexicon by either reliable people, by analogy etc. Therefore, this method is like a wrapper around our existing methods, rather than being used in conjunction with them. For example, the lexicon of dance includes words like tihai, raag, taal, and the way someone learns the meaning of these words is by observing artists in the field, trusting the statement of their music teach, and of course, a dictionary.
Next is the statement of a reliable person. Our parents tell us that a ball is a ball, and we believe it. An interesting tangent is that if we lived in a vaccum, and learnt that a ball was actually a horse, the only way it would be relevant is if we then had to socialize and use that word. This in turn reiterates how language cannot be private, and the meaning of words are only relevant when it is used by a population. This also implies that we are constantly learning meanings by employing these methods: if I learnt it incorrectly by a reliable person, I would be corrected by, say, lexicon, or context.
The speech behavior of elders is a behavioral method: the child learns by seeing what actions are invoked by the command of the elders. This is more nuanced because there is body language and tone. Multimodal learning gives the child more information about the meaning of the word, specifically how it relates to actions and what the underlying emotions can be. The final three methods are: context by the remaining part of the sentence, explanation from a trusted source, and proximity with well-known words (a specific case of contextuality). The prerequisite for contextuality is that we must have enough, if not complete, knowledge of what the rest of the words are meaning.