During a French lesson, head of physics relaxes (8)
I believe the answer is:
unclasps
'relaxes' is the definition.
Although both the answer and definition are verbs in their -s form, I can't understand how one could define the other.
'during a french lesson head of physics' is the wordplay.
'during' is an insertion indicator.
'a french' becomes 'un' ('a' in French).
'lesson' becomes 'class' (synonyms).
'head of' indicates taking the first letters.
The first letter of 'physics' is 'p'.
'un'+'class'='unclass'
'unclass' placed around 'p' is 'UNCLASPS'.
Can you help me to learn more?
(Another definition for unclasps that I've seen is " Releases fastener".)