Based on your understanding of the word connote, what seems like the most likely definition for denote?

The definition of the terminology 'connote' is to imply or indirectly suggest something. For example, the connotation of a dark sky, a dimly lit room and underlying tones of darkness connotes to a negative mood and effect.

Based on this understanding, we can infer that the most likely definition of the word 'denote' is to be a signal or symbol of explicit, more obvious meaning. For example, if a text states that Richard feels dizzy and lethargic, the author could perhaps be denoting to the fact that he is nauseous as his symptoms are clearly stated.

Connotations are usually implicit, whereas denotations are explicit.

Well, the definition for denote is indicate, or be a sign of. So, another word for denote could be signal, or designate.