However tense, meditation perhaps? (7)
I believe the answer is:
thought
'meditation perhaps?' is the definition.
(meditation is a kind of thought)
'however tense' is the wordplay.
'however' becomes 'though' (synonyms).
'tense' becomes 't' (abbreviation used in many dictionaries).
'though'+'t'='THOUGHT'
(Other definitions for thought that I've seen before include "Philosopher must master this" , "Thinking process" , "Deliberation" , "Meditation" , "Idea coming to mind" .)