gel

Short definition from Wiktionary

Noun

1. 1
   A semi-solid to almost solid colloid of a solid and a liquid, such as jelly, cheese or opal.
2. 2
   Any gel intended for a particular cosmetic use, such as for styling the hair.
3. 3
   A film of flexible transparent plastic (such as acetate, celluloid, or cellophane) suitable for making superimpositions or diapositives (image to overlay on other images, especially for overhead projectors); a digital virtual equivalent of this.
4. 4
   A girl.

Verb

1. 1
   To apply (cosmetic) gel to (the hair, etc).
2. 2
   To become a gel.
3. 3
   To develop a rapport.
4. 4
   To come together to form something; to cohere.