The Collaborative International Dictionary of English v.0.48:
Directly \Di*rect"ly\, adv.
1. In a direct manner; in a straight line or course. "To run
directly on." --Shak.
Indirectly and directly too
Thou hast contrived against the very life
Of the defendant. --Shak.
2. In a straightforward way; without anything intervening;
not by secondary, but by direct, means.
3. Without circumlocution or ambiguity; absolutely; in
No man hath hitherto been so impious as plainly and
directly to condemn prayer. --Hooker.
4. Exactly; just.
Stand you directly in Antonius' way. --Shak.
5. Straightforwardly; honestly.
I have dealt most directly in thy affair. --Shak.
6. Manifestly; openly. [Obs.]
Desdemona is directly in love with him. --Shak.
7. Straightway; next in order; without delay; immediately.
"Will she go now to bed?' ?Directly.'" --Shak.
8. Immediately after; as soon as.
Directly he stopped, the coffin was removed.
Note: This use of the word is common in England, especially
in colloquial speech, but it can hardly be regarded as
a well-sanctioned or desirable use.
Directly proportional (Math.), proportional in the order of
the terms; increasing or decreasing together, and with a
constant ratio; -- opposed to inversely proportional.
Syn: Immediately; forthwith; straightway; instantly;
instantaneously; soon; promptly; openly; expressly.
Usage: -- Directly, Immediately, Instantly,
Instantaneously. Directly denotes, without any delay
or diversion of attention; immediately implies,
without any interposition of other occupation;
instantly implies, without any intervention of time.
Hence, "I will do it directly," means, "I will go
straightway about it." "I will do it immediately,"
means, "I will do it as the very next thing." "I will
do it instantly," allows not a particle of delay.
Instantaneously, like instantly, marks an interval too
small to be appreciable, but commonly relates to
physical causes; as, the powder touched by fire