The words 'commencement' , 'compulsive', and 'conjunctive' occur only in Hamlet and in Othello, and in both plays they are restricted to a context of great passion. It is tempting to speculate on Shakespeare's associating all these words with the joining force of the Latin preposition 'cum', although in the first two instances the prefix has the intensifying meaning of the Latin word.
Polonius, expressing his views about Hamlet's strange behavior, says that "the origin and commencement of his grief / Sprung from neglected love" (Ham.3.1.177-178), and Iago reassures Roderigo that Desdemona' passion for Othello will soon diminish because of its "violent commencement" (Oth. 1.3.344).
In the case of 'compulsive' the context restriction is more precise since the word occurs near a "cold" word in a context of extreme passion. Hamlet uses "hot and cold" language to express his disgust at his mother's passion for Claudius
Rebellious hell,
83
If thou canst mutine in a matron's bones,
84
To flaming youth let virtue be as wax
85
And melt in her own fire. Proclaim no shame
86
When the compulsive ardure gives the charge,
87
Since frost itself as actively doth burn,
88
And reason [panders] will. (Ham. 3.4.82-88)
This hot and cold rhetoric is also implicit in Othello's famous lines:
453 Never, Iago.
Like to the Pontic Sea,
454 Whose icy current and compulsive
course
455 Nev'r [feels] retiring ebb, but
keeps due on
456 To the Propontic and the
Hellespont,
457 Even so my bloody thoughts, with
violent pace,
458 Shall nev'r look back, nev'r ebb
to humble love,
459 Till that a capable and wide
revenge
460 Swallow them up. (Oth. 3.3.453-460)
Claudius, speaking of Gertrude, says to Laertes that
14 She is so [conjunctive]
to my life and soul,
15 That, as the star moves not but in
his sphere,
16 I could not but by her. (Ham. 4.7.
14-16)
Iago allies himself with Roderigo in their joint hatred of Othello:
I
365
have told thee often, and I retell thee again and
366
again, I hate the Moor. My cause is hearted; thine
367
hath no less reason. Let us be conjunctive in our
368
revenge against him. (Oth.
1.3.364-368)
See the entry on 'extravagant' for other verbal links between Hamlet and Othello