For example, a landlady (6)
I believe the answer is:
letter
I believe this is a double definition.
'for example a' is the first definition.
('a' is an example)
'landlady' is the second definition.
(someone who 'lets')
(Other definitions for letter that I've seen before include "Alphabetic character" , "Written character - landlord" , "who may offer terms to residents?" , "Unit of alphabet" , "Alphabetic symbol" .)