sustain

Concise Oxford English Dictionary © 2008 Oxford University Press:
sustain/səˈsteɪn/

▶verb

• 1 strengthen or support physically or mentally.

  ■ bear (the weight of an object).

• 2 keep (something) going over time or continuously.

• 3 suffer (something unpleasant).

• 4 uphold or confirm the justice or validity of.

▶noun Music an effect or facility on a keyboard or electronic instrument whereby a note can be sustained after the key is released.

– derivatives
sustained adjective,
sustainedly adverb,
sustainer noun,
sustainment noun.

– origin ME: from OFr. soustenir, from L. sustinere, from sub- ‘from below’ + tenere ‘hold’.