Number one weakling not quite getting hold of sheep (3-3)

'number' is the definition.
Although both the answer and definition are verbs in their base form, I can't see how one could define the other.

'one weakling not quite getting hold of sheep' is the wordplay.
'one weakling' becomes 'weed'.
'not quite' means to remove the last letter (most but not all of the word).
'getting hold of' is an insertion indicator.
'sheep' becomes 'ewe' (a ewe is a female sheep).
'weed' with its final letter taken away is 'wee'.
'wee' enclosing 'ewe' is 'WEE-WEE'.

Can you help me to learn more?