Type of spaniel in season, mother-to-be essentially (8)
I believe the answer is:
springer
'type of spaniel' is the definition.
(I know that springer is a type of spaniel)
'season mother-to-be essentially' is the wordplay.
'season' becomes 'spring' (spring is a season).
'mother-to' becomes 'e' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'be' becomes 'are' (I've seen this in another clue).
'essentially' indicates the central letters.
The middle letter of 'are' is 'r'.
'spring'+'e'+'r'='SPRINGER'
'in' is the link.
Can you help me to learn more?
(Other definitions for springer that I've seen before include "Game dog" , "Type of spaniel" , "Large spaniel with wavy silky coat" , "Breed of spaniel" , "Kind of spaniel" .)