Reduplicated from 'adam; reddish -- (somewhat) reddish.
see HEBREW 'adam
H125. adamdam
אֲדַמְדָּם adjective reddish (compare Assyrian ada(m)mumu ? DlW) of leprous sores Leviticus 13:42 (דָּֿ֑ם) 13:49 (דָֹֿם); f. אֲדַמְדֶּמֶת 13:24; 13:43; דָֿ֑מֶת 13:19; feminine plural אֲדַמְדַּמֹּת 14:37.