Compel old boy to rest — good to get tucked in (6)
I believe the answer is:
oblige
'compel' is the definition.
(I know that compel can be written as oblige)
'old boy to rest good to get tucked in' is the wordplay.
I cannot quite understand how this works, but
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is located in the answer.
'boy' could be 'b' (abbreviation used in schools) and 'b' is found within the answer.
'good' could be 'g' (abbreviation) and 'g' is found in the answer.
'rest' could be 'lie' (synonyms) and 'lie' is found in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for oblige that I've seen before include "press!" , "Morally influence" , "serve" , "Compel (someone to do something)" , "Do favour or coerce" .)