Health is essential to happiness. (Health cannot be missing from happiness.)
https://takoboto.jp/?w=1253900
This dictionary says 欠くis a transitive verb; however, in this sentence it seems to be used as an intransitive verb (no apparent object). Why is that?
@ericaw
The original Japanese sentence, sourced from Tanaka Corpus (notoriously famous for its low quality), sounds very unnatural.
According to the Clozemaster sentence search, 4K Most Common Words Collection and N1 Collection have
ID: 173648 – 幸福には健康が{{不可欠}}です。
ID: 173650 – 幸福な人生には健康が{{不可欠}}です。
for the translation from ID: 240820 – Health is indispensable to a happy life.
You just need to practice with these two pairs and push the “ignore” button on ID: 175478 with the awkward phrase 欠くことができない.
Alternatively, you can say:
健康は幸せな人生 (or 幸福な人生) に欠かせない。
You can find other sentences with 欠かせない on 英辞郎.
I also give you “correct” example sentences with the phrase 欠く or 欠ける:
最近のメアリーはやる気に欠ける。or 欠く。= Mary lacks her enthusiasm for everything these days.
トムの主張は論拠に欠く。= Tom’s opinion doesn’t have rationales. (pron. トムのしゅちょうはろんきょにかく)