Entry 3 senses · 2 variants Webster, 1913 Signatory /sĭg'-nət-ôrˌ-ē/ · Sig·na·to·ry · IPA /ˈsɪɡ.nə.tɔː.ɹi/ a. n. 01 a. Relating to a seal; used in sealing. 1. Relating to a seal; used in sealing.[Obs.] 2. Signing; joining or sharing in a signature; as, signatory powers. 02 n. A signer; one who signs or subscribes; as, a conference of signatories. pl. -ries 1. A signer; one who signs or subscribes; as, a conference of signatories.