underappreciate
Verb
Meaning
(transitive) To not hold in sufficiently high esteem.
(intransitive) To not gain in value sufficiently.
Source: en.wiktionary.orgSynonyms
Examples
American audiences tend to underappreciate the British, but 240 years ago they were us: They were the most powerful nation on Earth. Their mercantile empire spanned the planet. They had the most potent and experienced army and navy the world had ever seen.