rotational

Etymology

It is formed from English rotation + -al.^[2][3][4] Rotation is from Latin rotātiō (“a turning about in a circle”), from rotō (“to turn round, revolve”),^[3][2] from the same source as rota (“wheel”).^[3] The OED compares the earlier rotary.^[2]

Earliest recorded meaning

Relating to the rotation of crops: 1771, in M. Peters's Winter Riches.^[2] Merriam-Webster gives the same year,^[5] while Etymonline dates the word to 1852, in the sense "acting in rotation".^[3]

Semantic evolution

The two senses of rotation gave the adjective two groups of meanings.^[2] From alternation came, besides the farming sense, "acting or done in rotation, by turns" (1780).^[2] From turning came "of the nature of rotation, relating to rotation" (1788), which the OED notes was rare before the late 19th century;^[2] Etymonline dates it to 1891.^[3] In physics it has been used since 1894 of the energy an atom or molecule has because it rotates, energy now known to be quantized,^[2][4] and in farming since 1920 of grazing animals on different areas of land in turn.^[2][4]

Timeline

• 1771 – relating to the rotation of crops.^[2][5]
• 1780 – acting or done in rotation.^[2]
• 1788 – relating to rotation or turning.^[2]
• 1894 – physics, of the rotational energy of atoms and molecules.^[2]
• 1920 – of rotational grazing.^[2]

Meanings

Adjective

1. Of, relating to or produced by rotation or turning about an axis: the rotational speed of a turbine.^[5][2][4]
2. (physics) Relating to the energy an atom or molecule has because it rotates.^[2][4]
3. (agriculture) Relating to the rotation of crops, or to a system of grazing animals on different areas in turn.^[2][4]
4. Acting or done in rotation, by turns.^[2][4][3]

Word family

• nonrotational
• rotational molding

Related words

• rotation
• rotate
• rotary
• rota

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f g Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b c Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster