That
That adverb - To a great degree.
What if
That and what if are semantically related in suppose that topic. You can use "That" instead a conjunction phrase "What if".
Mutual synonyms
Cite this Source
What if and That. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/that/what_if
That & What if. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/that/what_if>.
What if or That. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/that/what_if.
Google Ngram Viewer shows how "that" and "what if" have occurred on timeline