The words encyst, insist sound the same but have different meanings and spellings. Why do encyst, insist sound the same even though they are completely different words?
The answer is simple: encyst, insist are homophones of the English language.
To be enclosed within a cyst.
To enclose within a <xref>cyst</xref>.
To inclose in a cyst.
To inclose or become inclosed in a cyst or vesicle.
assert to be true
beg persistently and urgently
be emphatic or resolute and refuse to budge
To <xref>stand</xref> on; to <xref>rest</xref> upon; to <xref>lean</xref> upon. Used especially as a technical term in <xref>geometry</xref>.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License., from the GNU version of the Collaborative International Dictionary of English., from The Century Dictionary., from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved. and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.