Elucubrating, meaning to think or work out intensely and thoroughly, has several synonyms that can be used in its place. One possible synonym for elucubrating is cogitating, which means to ponder or consider deeply. Another possible synonym is ruminating, which means to think carefully and for a prolonged period.
You can also use the word musing, which means to be lost in thought or deep in contemplation. Similarly, if you are reflecting deeply or pondering, you could also consider the word meditating. Other possible synonyms include contemplating, pondering, and reflecting.
In conclusion, there are several synonyms for the word elucubrating, including cogitating, ruminating, musing, meditating, and reflecting, which can help add variety and depth to your writing.