All 5 Uses

solemn
in
Old Yeller
(Auto-generated)

It made me feel big and solemn and important in a way I'd never felt before.†
p. 4.6 *

solemn = very serious--possibly dignified
They were big solemn brown eyes and right pretty to look at; only when she fixed them on me, it always seemed like they looked clear through me and saw everything I was thinking.†
p. 48.9
Lisbeth slipped to the ground and stood staring at me with those big solemn eyes while her grandpa dismounted.†
p. 49.6
She stood with her hands behind her back, staring at me with her big solemn eyes.†
p. 102.1
She stared at me with big solemn eyes.†
p. 108.5

Definitions:

(1) (solemn)
in a very serious (and often dignified) manner
(2) (meaning too rare to warrant focus)
Less commonly, solemn can mean that something was done with great or appropriate ceremony. It can also be used to describe something as dark or undecorated.