Computer network, mostly imprecise, picked up inertia (7)
I believe the answer is:
languor
'inertia' is the definition.
(I have seen 'Dreamy inertia ' mean 'languor' so perhaps 'inertia' could also mean 'languor')
'computer network mostly imprecise picked up' is the wordplay.
'computer network' becomes 'lan' (LAN is an example).
'mostly' means to remove the last letter.
'imprecise' becomes 'rough' (I've seen this before).
'picked up' is a reversal indicator.
'rough' with its final letter taken off is 'roug'.
'roug' in reverse letter order is 'guor'.
'lan'+'guor'='LANGUOR'
(Other definitions for languor that I've seen before include "Pleasant inactivity" , "Apathy" , "tender softness" , "'Lassitude, lethargy (7)'" , "Weariness; relaxation" .)