keep, maintain, hold
Meaning: keep in a certain state, position, or activity; e.g., "keep clean"; "hold in place"; "She always held herself as a lady"; "The students keep me on my toes"
conserve, preserve, maintain, keep_up
Meaning: keep in safety and protect from harm, decay, loss, or destruction; "We preserve these archeological findings"; "The old lady could not keep up the building"; "children must be taught to conserve our national heritage"; "The museum curator conserved the ancient manuscripts"
sustain, keep, maintain
Meaning: supply with necessities and support; "She alone sustained her family"; "The money will sustain our good cause"; "There's little to earn and many to keep"
assert, asseverate, maintain
Meaning: state categorically
wield, exert, maintain
Meaning: have and exercise; "wield power and authority"
"Maintain firm hold upon Virtue.
To maintain the beet-root, the cane had to be taxed.
Roger was vexed, but he continued to maintain his calm manner.
Some maintain that all that is needed to make workmen more efficient is to feed them well.
Yet he would wait until five miles from the end, and then he felt that he could gain and maintain a lead.
It follows, therefore, that it is altogether impossible and unreasonable to maintain that there exists one intellect for all men.
The old monarchies would say that despite our superior numbers we're not able to maintain ourselves outside the defenses of Washington.
When others were present she would restrain herself somewhat, but with only Jane and myself, she could hardly maintain a seemly reserve.
Innocence is indeed a glorious thing; only, on the other hand, it is very sad that it cannot well maintain itself and is easily seduced.
There are many authors who maintain that the soul can act directly on the body and modify it, and this is what is called inter-actionism.