This term tends to limit itself to a specific set of experiences (experience converts to free awareness in direct proportion relative to the Temperature of the operator). The common placement of the term "Karma-Yoga" within the form of this era's popular methods of Yoga-As-Philosophy or Yoga-As-Occult-Science indicates either service (often people live in a purifying place and do free service involved in the upkeep or promotion of the place and/or guru-leadership) or "works" (in the sense of good deeds performed in the expectation of some salvational reward). These then receive further taxonomy into service or works performed with a doomed attitude, or an ecstatic attitude.
These practices serve a transformational-exo-esoteric purpose by creating the habit of service and work meant to be performed either with no reward (in the case of the most dignified aspect of the doomed attitude) or with some extremely delayed gratification either in the next life, afterlife, or after many more lives (in the case of the most dignified aspect of the ecstatic attitude). This, with a more combined lifestyle effort including daily zero-time (dhyana or "meditation" techniques without mantra) and daily focus-time (dharana or concentrative techniques including mantra or image (yantra), eventually redirects the feel-goods, detaching them from expectation and instead connecting them to the absence of expectation. Used with good result to defeat guilt.
What else can Karma-yoga mean?
Taking Karma to mean "action" and Yoga to mean "union" it can mean union with action. Martial arts approaches this by the numbers. Get better at punching and kicking, learn to respond instead of react, but quickly, efficiently, effectively. Empty the mind of all thought and everything comes naturally, but only with continual training. Continual discipline, usually performed alone for salvation, delayed gratification but additionally to achieve some type of harmony with the environment and the internal self, a unification of opposites that automatically supposes a third party that observes the union. At higher levels these practices, which begin with the body, mirror most forms of traditional tantric hatha yoga. Eventually leading to stillness either as the operator begins a still seated practice naturally, or when the operator dies (which appears unmistakably still at least in terms of neuronal transmission (which is really the only movement (let's face it))). These still seated practices also contain elements of focus (Dharana) and/or emptiness (Dhyana). Used with good result to defeat shame.
Ishvara pranidhana- self surrender or surrender to the personal god (little g god).
This path requires its participant to develop a devotion to personal divinity and sublimate the mind through constant concentration. All of life's decisions made by this source, in the absence of mind. Anxiety depletes and this unconscious decision maker feeds and grows larger and more capable of making decisions as a sculptor. Ultimately the practitioner seeks union with this internal ideal and sculpts the ideal through concentration (normally focus on a particular image). This procedure gets pushed below the conscious level after some time, and the results of this procedure then steer the activity of the user. Decision making sublimated. Used with good result to defeat the demon of trust.
Sanga Spandana- a confluence of vibration or throbbing or a community vibration or throbbing. If we possess some type of essential vibration unique to either a group or "ourselves", then perhaps the number of completely distinct "essential vibrations" in the wild exceeds no great number whatsoever. Then does everything not vibrate with some "essential vibration?"
Practicing a mantra slowly alters this "essential" vibration, attracting or repelling other sounds depending on the operators deep need for harmony or discord. Language grasps at trying to project these deep internal sounds, and (under these specific auspices) finding common ground with someone indicates some shared resonance. Idiosyncracy, internal dictionaries, body language, all muddy the effectiveness of this communication. But without mind, the operator can quickly learn the internally consistent language of another through awareness rather than observation, and even achieve some semblance of ability to speak back to the interlocutor.