Contemplate securing round bit of IT equipment (5)
I believe the answer is:
mouse
'bit of it equipment' is the definition.
(a computer mouse)
'contemplate securing round' is the wordplay.
'contemplate' becomes 'muse' (synonyms).
'securing' means one lot of letters goes inside another.
'round' becomes 'o' (round can mean a round object).
'muse' enclosing 'o' is 'MOUSE'.
(Other definitions for mouse that I've seen before include "Domestic rodent" , "Computer accessory" , "shy and timid type" , "Quiet person" , "Wimp" .)