No ball carried by university rugby forward, that’s clear (7)
I believe the answer is:
unblock
'clear' is the definition.
(I've seen this in another clue)
'no ball carried by university rugby forward' is the wordplay.
'no ball' becomes 'nb' (this could be a standard abbreviation of which I'm unaware).
'carried by' means one lot of letters goes inside another.
'university' becomes 'u' (abbreviation for university).
'rugby forward' becomes 'lock' (lock is an example).
'u'+'lock'='ulock'
'nb' placed inside 'ulock' is 'UNBLOCK'.
'that's' is the link.
Can you help me to learn more?
(Other definitions for unblock that I've seen before include "Clear (drains, etc)" , "Remove an obstruction from" .)