Guardian 27,699

[professorplum13]

43a Repeatedly went and persevered (9) ?E?T?O?NG
47a Snake in secret surroundings (5) ???A?
53a Bird getting stronger gaining weight (7) ?A?????

[Toorak]

Kept going
Q boat
Waxwing

[bookbinder]

43a kept going (4,5)

[professorplum13]

Thank you Toorak and bookbinder for your very quick replies!

[Lie-in King]

43a Kept going (one of the extra two-word answers)
47a Q-boat (themed) - 'boa' (in) 'QT' (secret)
53a Waxwing - 'w(eight)' (in) 'waxing' (getting stronger)

[Captain2]

43 Kept going

I believe there is a preamble to this Xword (but don't know what it says)

[Toorak]

26 answers are undefined. Each has a single letter before or after a word (q boat in this case) with each of the letters of the alphabet represented once). But the number of letters given is for the total (e.g. 5 rather than 1, 4)

[Toorak]

Also, in a few other cases the solution is two words but this is not indicated by the numbers provided - for example 9 is given rather than 3, 6

[Captain2]

Thanks Toorak - clear as mud now ;0))
(never have liked the Guardian crossword)