maintain
main-tain
verb
To continue to have or keep something at a certain level.
"She struggled to maintain her composure."
verb
To assert something to be true, especially in an argument.
"He maintained his innocence throughout."
verb
To keep something in good condition or working order.
"We must maintain the garden regularly."
Thesaurus
Synonyms: defend, keep, observe, preserve, keep up, conserve, uphold, exert, wield, asseverate, assert, sustain