In lobby, at centre, Ohioan occasionally might mingle (6)
I believe the answer is:
hobnob
'mingle' is the definition.
Both the answer and definition are verbs in their base form.
Perhaps you can see an association between them that I can't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for hobnob that I've seen before include "Spend friendly time together" , "Socialise (especially with posher people)" , "Rub elbows with the biscuit?" , "Feasible" , "Socialise as with the rich and famous" .)