Yes, lining is a Scrabble word!

Verb

1. Be in line with; form a line along

2. Cover the interior of

3. Make a mark or lines on a surface

4. Mark with lines

5. Fill plentifully

6. Reinforce with fabric

Noun

1. A protective covering that protects an inside surface

2. A piece of cloth that is used as the inside surface of a garment

3. Providing something with a surface of a different material

4. The act of attaching an inside lining (to a garment or curtain etc.)