As pyjamas often tear, put in tip (6)
I believe the answer is:
stripy
'as pyjamas often' is the definition.
I can't judge whether this defines the answer.
'tear put in tip' is the wordplay.
'tear' becomes 'rip' (rip is a kind of tear).
'put in' means one lot of letters goes inside another.
'tip' becomes 'sty' (I can't explain this - if you can you should believe this answer much more).
'rip' put within 'sty' is 'STRIPY'.
Can you help me to learn more?
(Other definitions for stripy that I've seen before include "Marked with lines" , "Like many blazers" .)