One such word is elastic.
expandable (I know its not 7!) I hope this helped!(:
elastic, spandex, or tensile
The word Mollusk is a 7 letter word.
The 7 letter word is "Capsule"
A 7-letter word for "far" is "distant."
A 7-letter word for barely boiled is "poached".
Ability is a 7 letter word.
pontoon
Oh, dude, you're really testing my brain cells here. Let me think... Oh, wait, I got it! The word is "silicon." Like, you know, the stuff that powers our devices and makes us all addicted to scrolling through memes.
Something that can get longer than it's original size
Can't get a 7 letter word with only 6 letters. The 6 letter word is DESIST.
Edifice is a 7 letter word for building.