選手【せんしゅ】
player (of a sport), athlete, team member
選挙【せんきょ】
election
選ぶ【えらぶ】
to choose, to select
予選【よせん】
preliminary contest, qualifying round, trial, heat, primary
当選【とうせん】
being elected, being selected (for a prize, etc.), winning
選択【せんたく】
choice, selection, option
選出【せんしゅつ】
election, selection, choice
抽選【ちゅうせん】
lottery, raffle, drawing (of lots)
選定【せんてい】
selection
入選【にゅうせん】
being selected (for a prize, exhibition, etc.), being accepted, winning
改選【かいせん】
re-election
選択科目【せんたくかもく】
elective subject or course
互選【ごせん】
election by mutual vote, election from within a committee (party, etc.), internal vote
普通選挙【ふつうせんきょ】
universal suffrage
精選【せいせん】
careful selection