ひっけい
indispensable; essential; must-have; handbook
Common word
No-adjective, Noun, suffix
Noun
TOEICの学習がくしゅうに限かぎらず、英語えいごを学まなぶのであれば英和辞典えいわじてんは必携ひっけいの書しょの一ひとつでしょう。
An English-Japanese dictionary is surely a must have book, not just for those taking TOEIC, but for all studying English.