Touch on ship's cat (7)

I believe the answer is:

tigress

I'm a little stuck... Click here to teach me more about this clue!

'cat' is the definition.
(I know that tigress is a type of Panthera tigris)

'touch on ship's' is the wordplay.
'touch on' becomes 'tigre' (I can't justify this - if you can you should believe this answer much more).
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'tigre'+'ss'='TIGRESS'

Can you help me to learn more?

(Other definitions for tigress that I've seen before include "Wild woman" , "Female big cat" , "Large she-cat" , "Fierce woman" , "Amazon, say" .)

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app