Register taxi in house in the woods? (3,5)
I believe the answer is:
log cabin
'house in the woods?' is the definition.
(log cabins are often found in woods)
'register taxi in' is the wordplay.
'register' becomes 'log' (a log is a register).
'taxi' becomes 'cab' (synonyms).
'log'+'cab'+'in'='LOG-CABIN'
(Other definitions for log cabin that I've seen before include "Type of chalet" , "Hut, as in the Wild West" , "Simple dwelling" , "Wooden home" , "Pioneer's hut" .)