Wellington perhaps back from Waterloo, tense beneath lady's fingers (7)
I believe the answer is:
gumboot
'wellington' is the definition.
(I've seen this before)
'back from waterloo tense beneath lady's fingers' is the wordplay.
'back from' says to take the final letters (the letter at the back of the word).
'tense' becomes 't' (grammatical abbreviation).
'beneath' says to put letters next to each other (in a down clue, some letters go below others).
'lady's fingers' becomes 'gumbo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The final letter of 'waterloo' is 'o'.
'o'+'t'='ot'
'ot' after 'gumbo' is 'GUMBOOT'.
'perhaps' acts as a link.
Can you help me to learn more?
(Other definitions for gumboot that I've seen before include "Wader" , "Wellington" , "Waterproof footwear" .)