Celebrated weekend with present on first night (5)
I believe the answer is:
known
'celebrated' is the definition.
(similar in meaning)
'weekend with present on first night' is the wordplay.
'weekend' becomes 'k' (I've seen this in other clues).
'with' is a charade indicator (letters next to each other).
'present' becomes 'now' (both can mean the current period).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'first night' becomes 'n' (kst letter of 'night').
'k'+'now'+'n'='KNOWN'
(Other definitions for known that I've seen before include "Acknowledged" , "Experienced" , "In the public domain?" , "Recognised, familiar" , "Widely recognized" .)