We use the deviation call "airspeed." I don't like "speed" because it is too vague. "Speed" could be vertical speed or airspeed.
If the pilot flying is aware of his status at all, he knows he's deviating. The call is a reminder that not only is he deviating, but that he needs to correct. We use the call "Airspeed" followed by the response "correcting." The only exception to that response might be a circumstance in which a gross error occurs between crewmember's airspeed indicators, in which case the pilot flying should really say something about his or her speed. I've seen that happen a few times over the years in different aircraft.
We only use "airspeed" as a deviation call, except for one time during the takeoff, when the same call is used to denote airspeed-alive, or that the first indication of airspeed indicator movement has happened. The call is intended only to draw attention to the airspeed indicator. The attitude display has a fast/slow indicator for the airspeed reference bug, and will give an immediate indication of the airspeed.
Our standard call is intended to be made if airspeed if 10 knots fast, or if it's below "bug" speed (the intended speed for a particular phase of flight and configuration). It's most commonly expected during an approach, but could be heard in cruise under an unusual circumstance. A drop in speed due to unusual wave action, shear, or an autothrottle problem, for example.
During the approach, we have two calls at 1000' and 500' above touchdown zone elevation that don't involve airspeed, but altitude and pitch. The flight engineer will add the vertical speed and declare the status of any instrument flags. When the word speed is used by the engineer in that event, he will specify "vertical speed" in order that it not be confused with airspeed. If the flight engineer notes an airspeed discrepancy or outside the boundaries of the deviation criteria, he may also call "airspeed."
While I have met check airman who will jump down someone's throat for any extra verbiage (such as "thanks" or "please"), most are quite willing to add a quick "watch your airspeed," or "you're fast," or "don't get slow." Those are non-standard, but fortunately most have enough common sense to do the same as we used to do with police radio: when in doubt, fall back to plain English. It still works.
Insofar as standard call-outs, I think "airspeed" works, because the call is only intended to remind the pilot flying of what he should already know. If there's any ambiguity, or room for misunderstanding, then the person making the call should clarify that in plain English, or the person flying should seek clarification. While "airspeed" works, I agree that it could also be improved. "Airspeed high" or "airspeed low" takes very little extra time and conveys a lot more information.
We do have various deviation calls that are also equally neutral, which might be improved. "Glideslope" for example, could be improved with "above glideslope" or "below glideslope."