With support, most of them get through first set? (6)
I believe the answer is:
teethe
'get through first set?' is the definition.
'teethe' can be an answer for 'get' (teething is a kind of getting). I'm unsure of the 'through first set?' bit.
'with support most of them' is the wordplay.
'with' means one lot of letters go next to another.
'support' becomes 'tee' (tee is a kind of support).
'most of' means to remove the last letter.
'them' with its last letter taken off is 'the'.
'tee'+'the' is 'TEETHE'.
Can you help me to learn more?
(Other definitions for teethe that I've seen before include "Of baby, having first gum growth" , "Develop incisors, say" , "Grow gnashers!" , "Of baby, grow molars, canines etc" , "Cut one's dental fixtures" .)