This is like a "magic" word because it can have several meanings.
Like you said before, the dictionary says (to throw) but "echar" can be interpreted in different ways, such as:
Me echaron del trabajo. (get fired)
Hay que echarle más sal al guisado. (put)
Echarnos una botana. (eat)
Vamos a echarnos una cerveza. (drink)
Echame una mano. (help, literally give me a hand)
Echar piedras al río. (throw)
Echarle sentimiento. (to be sentimental towards something)
Echarle coco/cabeza. (it's an idiom, that means "to weigh")
depending on the complement/context "echar" can mean either "do" or "don't do". you can find this in idioms like:
Echar la hueva. (be lazy, don't do anything)
Échale ganas. (a way to cheer up or encourage to do something)
Echar pasión. (making out or hanky panky time, jaja!)
probably there are some other meanings left, I cannot recall now, anyway don't read too much into this, with practice you will get all the meanings without hesitation.