Plant everyone installs at first with hesitation (6)
I believe the answer is:
allium
'plant' is the definition.
The answer is an example.
'everyone installs at first with hesitation' is the wordplay.
'everyone' becomes 'all' (all people).
'at first' indicates taking the first letters.
'with' says to put letters next to each other.
'hesitation' becomes 'um' (um is said in hesitation).
The first letter of 'installs' is 'i'.
'all'+'i'+'um'='ALLIUM'
(Other definitions for allium that I've seen before include "Plant of onion family" , "Bulbous plant" , "Plant of onion genus" , "Onion/garlic genus" .)