a spare; a reserve
a reserve of food
keep some money in reserve in case of (an) emergency
We have no spare room for guests.
make a preliminary investigation
The batteries may wear out. Let's take some spares [extras].
reserve duty; service in the first reserves
a reserve officer
a reserve fund; a fund in reserve
a reserve (corps); the reserves
((go to)) a cramming [coaching] school
Yobiko are private schools or institutions designed to prepare students for university and college entrance examinations. The great majority of students at yobiko are high school graduates who have failed in entrance examinations at least once and are preparing for the following year's exams. Some high school students also go to yobiko after school or in the evening. The private schools which prepare younger students for junior or senior high school entrance exams are called juku. Yobiko and juku are two major businesses in the entrance exam support industry.（意訳：大学など上級学校への入学試験に備え受験指導をする学校．予備校生の大多数は浪人生だが，現役の高校生の中には学校が終わった後で予備校へ行く生徒もいる．小中学生を主な対象とした，中学，高校受験のための塾と並んで受験産業の大きな柱である）
preliminaries; spadework; groundwork ((for))
preliminary [working-level] negotiations
予備交渉をする negotiate beforehand; have a preliminary talk
a preliminary election；《米》 a primary
a pilot survey
a reserve [contingency] fund
Seventy thousand yen was set aside 「as a reserve fund [for emergency expenses].
〔予備の部品〕spare parts；〔非常準備品〕spares；〔予備の貯蔵品〕a reserve supply