Vav is a hook. See this post for a description of the form of the letter and its role as a hook in the tabernacle. In Exodus 27:11 we have the instruction for the building of the tabernacle including the silver hooks of the pillars.
וָוֵי הָעַמֻּדִים וַחֲשֻׁקֵיהֶם, כָּסֶף [vavei ha'amudim vahasheqeihem kaseph] The hooks of the pillars and their attachments of silver.
חשק is a verb meaning to love, be attached to, long for, or be joined. As in English, 'attachment' can be literal - a hook to a pole, or figurative.
We have met several vavs in our existing vocabulary and verses.