The Collaborative International Dictionary of English v.0.48:

Instruction \In*struc"tion\, n. [L. instructio: cf. F.
   instruction.]
   [1913 Webster]
   1. The act of instructing, teaching, or furnishing with
      knowledge; information.
      [1913 Webster]

   2. That which instructs, or with which one is instructed; the
      intelligence or information imparted; as:
      (a) Precept; information; teachings.
      (b) Direction; order; command. "If my instructions may be
          your guide." --Shak.

   3. (Computers) a segment of coded data that is interpreted by
      a computer as a command to perform an operation or series
      of operations. The term instruction is applied to both the
      electronic form of the data as represented in and executed
      by the computer, and to any line of written computer code
      which is interpreted as one instruction by a compiler. A
      computer program is comprised of one or more
      instructions.

   Note: Instructions as contained in a program are formulated
         in a programming language, which may be an assembly
         language, in which one instruction corresponds to one
         command executed by the coputer, or in a higher-level
         programming language, in which one instruction may
         represent one of many instructions in assembly
         language. Higher-level programming languages include,
         for example, FORTRAN, ALGOL, ADA, C, "C++", COBOL, and
         JAVA; each of these languages have their own
         distinctive set of allowable instructions.

   Syn: command, statement, line of code, program line.
        [PJC]

   Syn: Education; teaching; indoctrination; information;
        advice; counsel. See Education.
        [1913 Webster]

WordNet (r) 3.0 (2006):

instruction
    n 1: a message describing how something is to be done; "he gave
         directions faster than she could follow them" [syn:
         direction, instruction]
    2: the activities of educating or instructing; activities that
       impart knowledge or skill; "he received no formal education";
       "our instruction was carefully programmed"; "good classroom
       teaching is seldom rewarded" [syn: education,
       instruction, teaching, pedagogy, didactics,
       educational activity]
    3: the profession of a teacher; "he prepared for teaching while
       still in college"; "pedagogy is recognized as an important
       profession" [syn: teaching, instruction, pedagogy]
    4: (computer science) a line of code written as part of a
       computer program [syn: instruction, command, statement,
       program line]

The Free On-line Dictionary of Computing (19 January 2023):

machine instruction
instruction

    The smallest element of a machine code program.

   (2009-06-23)