One's vocabulary size or the ability to use words effectively in a language; a measure of reading, comprehension, and expressive ability.
語彙力が足りなくて新聞が読みづらい。
My lack of vocabulary makes it hard to read newspapers.
語彙力を増やすには多くの読書と復習が必要だ。
To increase vocabulary, a lot of reading and review is necessary.
子どもの語彙力を伸ばすために、毎晩絵本を読み聞かせている。
I read picture books aloud every night to help grow my child's vocabulary.
TOEFLのスコアは語彙力に大きく左右されることが多い。
TOEFL scores are often greatly influenced by vocabulary knowledge.