Cannon fodder is an informal, derogatory term for military personnel who are regarded or treated as expendable in the face of enemy fire. The term is generally used in situations where soldiers are forced to deliberately fight against hopeless odds (with the foreknowledge that they will suffer extremely high casualties) in an effort to achieve a strategic goal. An example is the trench warfare in World War I. The term may also be used (somewhat pejoratively) to differentiate infantry from other forces (such as artillery, air force or the navy), or to distinguish expendable low-grade or inexperienced soldiers from supposedly more-valuable veterans.
Origins of the term 
The concept of soldiers as fodder, as nothing more than "food" to be consumed by battle, dates back to at least the sixteenth century. For example, in William Shakespeare's play Henry IV, Part 1 there is a scene where Prince Henry ridicules John Falstaff's pitiful group of soldiers. Falstaff replies to Prince Henry with cynical references to gunpowder and tossing bodies into mass grave pits, saying that his men are "good enough to toss; food for powder, food for powder; they'll fill a pit as well as better [men]..."
The supposedly first attested use of the expression "cannon fodder" belongs to a French writer, François-René de Chateaubriand. In his anti-Napoleonic pamphlet "De Buonaparte et des Bourbons", published in 1814, he criticized the cynical attitude towards recruits that prevailed in the end of Napoleon's reign: "On en était venu à ce point de mépris pour la vie des hommes et pour la France, d'appeler les conscrits la matière première et la chair à canon" — "the contempt for the lives of men and for France herself has come to the point of calling the conscripts 'the raw material' and 'the cannon fodder'."
Human wave attacks 
Cannon fodder infantry are the core participants in human wave attacks, where massive waves of poorly armed, poorly trained, and ill-equipped soldiers are sent in a charging attack designed to overwhelm defenders with numbers rather than superior strategy, movement, or technology.
These attacks are popular among militaries which possess very large numbers of conscript soldiers, but lack the means or funding to train or arm them to the same standard as their enemy.
See also 
- Forlorn hope, the initial wave of troops attacking a fortress or other strongpoint, who usually took terrible casualties.
- Redshirt, a character whose sole purpose is to die violently soon after being introduced. This term was originally used to describe the red-shirted security personnel of the original Star Trek series.
- Mook, from mook jung (Cantonese for "dead wood" or "wooden dummy") - the same but on the enemy's side.
- Sacrificial lamb, a metaphorical reference for a person who has little if any chance of surviving an upcoming challenge, but seeks to sacrifice him or herself for the common good.
- Human shield, a military tactic to use civilians to buffer valuable targets
- Meat shield, informal and often derogatory expression for someone put forth to absorb an attack or shelter another.
- Volkssturm, a hastily trained and equally poorly equipped paramilitary force used by Germany in the end of the Second World War.
- Penal military unit
- Principle of Evil Marksmanship
- Zerg rush, a pre-preemptive attack with a weak force in the game Starcraft
- Jobber, a pro-wrestler booked solely to lose matches and make his opponents look dominant.
- See, e.g., American Heritage Dictionary of the English Language.
- (French) "De Buonaparte et des Bourbons" — full text in the French Wikisource.