Submitted by György Chityil ... on Sat, 01/20/2018 - 01:10 Hierarchy: VerbDescription: {{idiomatic|ambitransitive}} To make or become mentally tougher.Ngram: toughen upNgram Text: toughen upSource: WiktionaryIssue: 0Wiktionary tag: ambitransitiveNgram Count: 2
