Less than four of us (3)
I believe the answer is:
our
'of us' is the definition.
(I've seen this before)
'less than four' is the wordplay.
'OUR' is hidden in amongst the letters.
However, I'm unsure how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for our that I've seen before include "Belonging to us" , "'-- House' (Madness song)" , "''Now is the winter of ... discontent'' (Richard III)" , "group possession?" , "Relating to us" .)