All 4 Uses

relinquish
in
The Giver
(Edited)

Each family member, including Lily, had been required to sign a pledge that they would not become attached to this little temporary guest, and that they would relinquish him without protest or appeal when he was assigned to his own family unit at next year's Ceremony.
p. 42.9 *

relinquish = surrender (give away)
Jonas never found the Ceremony of Ten particularly interesting — only time-consuming, as each child's hair was snipped neatly into its distinguishing cut: females lost their braids at Ten, and males, too, relinquished their long childish hair and took on the more manly short style which exposed their ears.
p. 46.6

relinquished = gave up
We relinquished color when we relinquished sunshine and did away with differences.
p. 95.8
We relinquished color when we relinquished sunshine and did away with differences.
p. 95.8

Definitions:

(1) (relinquish)
to give something up, or to let go of something -- typically an idea, position or possession
(2) (meaning too rare to warrant focus)