Bowled over when first to slip on the glove (7)
I believe the answer is:
smitten
'bowled over' is the definition.
(I've seen this before)
'first to slip on the glove' is the wordplay.
'first to' says to take the initial letters.
'on' says to put letters next to each other.
'the glove' becomes 'mitten' (mitten is a kind of glove).
The initial letter of 'slip' is 's'.
's'+'mitten'='SMITTEN'
'when' acts as a link.
(Other definitions for smitten that I've seen before include "Severely afflicted" , "Infatuated with mittens" , "Head over heels in love" , "Obsessed (when in love?)" , "Deeply in love" .)