Distend (verb)

1. To stretch or swell out by or as if by internal pressure.
2. To cause to expand or become distended.

Origin:

Late middle english: from latin distendere, from dis- "apart" + tendere "stretch".

Examples:

1. The balloon distended as the air was pumped into it.
2. His stomach distended after eating too much.
3. The muscles distended as he lifted the weights.
4. The blood vessels distended with the increase in blood flow.
5. The fabric distended as it was stretched over the frame.