Drop article into cot? (4)
I believe the answer is:
bead
'drop' is the definition.
(I know that drop can be written as bead)
'article into cot?' is the wordplay.
'article' becomes 'a' (English indefinite article).
'into' means one lot of letters goes inside another.
'cot?' becomes 'bed' (cot is a type of bed).
'a' inserted within 'bed' is 'BEAD'.
(Other definitions for bead that I've seen before include "Part of a necklace" , "Drop of liquid on a surface" , "Small drop of moisture" , "Drop, part of rosary" , "Round piece of glass, etc" .)