Hi
Can't find a death for Thomas Meakins for that period (in fact I couldn't find anything concrete for a Thomas and Ann), however, a couple of Williams' (he may have been William Thomas)...
He wasn't on the 1841 census with wife and daughter; he may have died or lived elsewhere.
Source, Free BMD:
June 1840, William Meakins, Potterpury. V. 15, P. 250.
March 1841, William Meakins, potterspury. V. 15, P. 250.
There was nothing significant in 1838/39 apart from a Zillah Meakins.
There a few Meakins on the BMD in the 1840's if you are looking for other family members.
Hope this may be of some use.
Regards
Geoff