Fish got right inside a piece of timber? (5)
I believe the answer is:
bream
'fish' is the definition.
(bream is a kind of fish)
'right inside a piece of timber?' is the wordplay.
'right' becomes 'r' (common abbreviation).
'inside' is an insertion indicator.
'a piece of timber?' becomes 'beam' (I've seen this before).
'r' put into 'beam' is 'BREAM'.
'got' acts as a link.
(Other definitions for bream that I've seen before include "Broad, thin fish" , "Fish - British classical guitarist, b. 1933" , "Amber (anag) - fish" , "Fish of the carp family" , "Edible fish" .)