Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
gĭngīva, ae, f., a gum: inter dentem et gingivam, Cels. 6, 13; cf. Cat. 39, 19; so in sing., Plin. 30, 3, 8, § 26; Juv. 10, 200.
In plur., Cels. 6, 13; 7, 12; 2, 1; 2, 7 et saep.; Plin. 29, 2, 10, § 37; 30, 3, 8, § 24; Cat. 97, 6.