toss vs throw back

toss is a noun but throw back is not a noun.

Word	Noun	Adjective	Verb	Adverb
toss	Yes	No	Yes	No
throw back	No	No	Yes	No

As verbs, throw back is a hyponym of toss; that is, throw back is a word with a more specific, narrower meaning than toss:

Other hyponyms of toss include submarine, lag, toss back.

toss (noun)	throw back (noun)
(sports) the act of throwing the ball to another member of your team
the act of flipping a coin
an abrupt movement

toss (verb)	throw back (verb)
agitate	throw back with a quick, light motion
throw or toss with a light motion
throw carelessly
lightly throw to see which side comes up
move or stir about violently
throw or cast away