enstrengthen

From en- +‎ strengthen.

• (Received Pronunciation) enPR: ĕnstrĕngʹthə̆n, IPA^(key): /ɛnˈstɹɛŋθə̆n/

enstrengthen (third-person singular simple present enstrengthens, present participle enstrengthening, simple past and past participle enstrengthened)

1. (obsolete, transitive) Render strong or stronger; strengthen.

• See also Thesaurus:strengthen

• “†enˈstrengthen, v.” listed in the Oxford English Dictionary [2^nd Ed.; 1989]