Being affectionate, yearn to embrace a number (6)
I believe the answer is:
loving
'being affectionate' is the definition.
(similar in meaning)
'yearn to embrace a number' is the wordplay.
'yearn' becomes 'long-' (synonyms).
'to embrace' indicates putting letters inside.
'a number' becomes 'vi' (VI is an example).
'long' going around 'vi' is 'LOVING'.
(Other definitions for loving that I've seen before include "Doting" , "Showing great affection" , "See 13" , "'Friday's child is . . . . . . and giving'" , "Affectionate and amorous" .)