This is the 9926th most frequent Turkish word.
açıcı
Opener or unclogger.
Here, the word 'açıcı' refers to a tool or a device used to open something, which typically in this instance means a 'door opener'.
Kapıyı açıcı ile açtım.
I opened the door with the opener.
In this sentence, 'açıcı' implies something that is illuminating or providing clarity, hence referring to the figurative meaning as 'enlightening'.
Bu konuşma çok açıcıydı.
This speech was very enlightening.
Again, in this context, 'açıcı' designates a physical opener, specifically one provided or included for convenience.