The Collaborative International Dictionary
Invitatories
Invitatory \In*vi"ta*to*ry\, n.; pl. Invitatories. [LL. invitatorium: cf. F. invitatoire.] That which invites; specifically, the invitatory psalm, or a part of it used in worship.
Wiktionary
invitatories
n. (plural of invitatory English)