Pretty basic question, I just want to know if it is possible to make verbs unseen by the player until some event allows it to be seen in the drop down menu.

I think the answer is "no"...
But you can add and remove verbs as needed in the game...

as DarkLizaerd said:

first, don't have the desired Verb(s) within/added-to the desired Object(s)' built-in 'displayverbs' and/or 'inventoryverbs' initially

then, as desired within your game (when-ever/where-ever for your desired action/s): add/remove verbs

https://docs.textadventures.co.uk/quest/display_verbs.html

the displayment of Verbs during game play (as clickable buttons in the panes on the right side and hyperlinks in thebig text box on the left side) is controlled by the built-in 'displayverbs' and/or 'inventoryverbs' StringList Attributes on your Objects

Thank you!