Entry 1 sense Webster, 1913 Therein /thĕr-ĭn'/ · There·in · IPA /ˈðɛəɹˈɪn/ 01 adv. In that or this place, time, or thing; in that particular or respect. 1. In that or this place, time, or thing; in that particular or respect. “He pricketh through a fair forest, Therein is many a wild beast.” — Chaucer. “Bring forth abundantly in the earth, and multiply therein.” — Gen. ix. 7. “Therein our letters do not well agree.” — Shak.