必携 ひっけい
hi' kei

Suffix
no-Adjective

1. indispensable; essential; must-have

TOEICの学習 がくしゅう かぎらず、英語 えうご まなぶのであれば英和 えうわ辞典 じてん必携 ひっけい しょ ひとつでしょう。
tōikkuno gakushū ni kagirazuēgō manabu nodeareba ēwajitenwa hikkēno shono hi. totsudeshō
An English-Japanese dictionary is surely a must have book, not just for those taking TOEIC, but for all studying English.
Noun

2. handbook; manual; vade mecum