17-letter words starting with l
- locomotive engine — a self-propelled engine driven by steam, electricity, or diesel power and used for drawing trains along railway tracks
- loggerhead shrike — a common, North American shrike, Lanius ludovicianus, gray above and white below with black wings, tail, and facial mask.
- loggerhead turtle — a sea turtle, Caretta caretta, having a large head: now greatly reduced in number.
- logic programming — (artificial intelligence, programming, language) A declarative, relational style of programming based on first-order logic. The original logic programming language was Prolog. The concept is based on Horn clauses. The programmer writes a "database" of "facts", e.g. wet(water). ("water is wet") and "rules", e.g. mortal(X) :- human(X). ("X is mortal is implied by X is human"). Facts and rules are collectively known as "clauses". The user supplies a "goal" which the system attempts to prove using "resolution" or "backward chaining". This involves matching the current goal against each fact or the left hand side of each rule using "unification". If the goal matches a fact, the goal succeeds; if it matches a rule then the process recurses, taking each sub-goal on the right hand side of the rule as the current goal. If all sub-goals succeed then the rule succeeds. Each time a possible clause is chosen, a "choice point" is created on a stack. If subsequent resolution fails then control eventually returns to the choice point and subsequent clauses are tried. This is known as "backtracking". Clauses may contain logic variables which take on any value necessary to make the fact or the left hand side of the rule match a goal. Unification binds these variables to the corresponding subterms of the goal. Such bindings are associated with the choice point at which the clause was chosen and are undone when backtracking reaches that choice point. The user is informed of the success or failure of his first goal and if it succeeds and contains variables he is told what values of those variables caused it to succeed. He can then ask for alternative solutions.
- logical operation — Boolean operation.
- lombrosian school — a school of criminology, promulgating the theories and employing the methods developed by Lombroso.
- long in the tooth — (in most vertebrates) one of the hard bodies or processes usually attached in a row to each jaw, serving for the prehension and mastication of food, as weapons of attack or defense, etc., and in mammals typically composed chiefly of dentin surrounding a sensitive pulp and covered on the crown with enamel.
- long island sound — an arm of the Atlantic between Connecticut and Long Island. 90 miles (145 km) long.
- longitudinal wave — a wave in which the direction of displacement is the same as the direction of propagation, as a sound wave.
- loose-joint hinge — a hinge having a knuckle formed from half of each flap, and with the upper half removable from the pin.
- loose-leaf binder — a hard cover with metal rings inside which is used to hold loose pieces of paper
- lord of the flies — a novel (1954) by William Golding.
- lose the exchange — to lose a rook in return for a bishop or knight
- lost in the noise — Synonym lost in the underflow. This term is from signal processing, where signals of very small amplitude cannot be separated from low-intensity noise in the system. Though popular among hackers, it is not confined to hackerdom; physicists, engineers, astronomers, and statisticians all use it.
- louisiana tanager — western tanager.
- low-hanging fruit — the fruit that grows low on a tree and is therefore easy to reach
- low-velocity zone — a layer or zone in the earth in which the velocity of seismic waves is slightly lower than in the layers above and below. The asthenosphere is thought to be such a zone
- lowbush blueberry — a shrub, Vaccinium angustifolium, of eastern North America, having small, white flowers and blue-black fruit.
- lower forty-eight — the forty-eight conterminous states of the United States
- lower paleolithic — See under Paleolithic.
- luggage insurance — insurance against the loss of luggage while travelling
- luminous efficacy — the quotient of the luminous flux of a radiation and its corresponding radiant flux
- luminous exitance — the ability of a surface to emit light expressed as the luminous flux per unit area at a specified point on the surface
- lumpenproletariat — the lowest level of the proletariat comprising unskilled workers, vagrants, and criminals and characterized by a lack of class identification and solidarity.
- lymphadenopathies — Plural form of lymphadenopathy.
- lymphangiographic — Relating to lymphangiography.
- lymphocytopoiesis — Lymphopoiesis.
- lyon king of arms — the chief herald of Scotland