Like a number commonly seen having a coffee (7)
I believe the answer is:
arabica
'coffee' is the definition.
(type of coffee plant)
'like a number commonly seen having a' is the wordplay.
'like a number commonly seen' becomes 'Arabic' (as in Arabic numerals).
'having' means one lot of letters go next to another.
'arabic'+'a'='ARABICA'
(Other definitions for arabica that I've seen before include "Variety of coffee beans" , "sort of bean" , "African tree cultivated for coffee" , "hot beverage" , "Variety of coffee bean" .)