shallow

Etymology

From Middle English schalowe (“not deep, shallow”); apparently related to Middle English schalde, schold, scheld, schealde (“shallow”), from Old English sċeald (“shallow”), from Proto-Germanic *skal-, from Proto-Indo-European *(s)kelh₁- (“to parch, dry out”). Related to Low German Scholl (“shallow water”). See also shoal.

adj

1. Having little depth; significantly less deep than wide.
   This crater is relatively shallow.
   Saute the onions in a shallow pan.
2. Extending not far downward.
   The water is shallow here.
3. Concerned mainly with superficial matters.
   It was a glamorous but shallow lifestyle.
4. Lacking interest or substance.
   The acting is good, but the characters are shallow.
5. Not intellectually deep; not penetrating deeply; simple; not wise or knowing.
   shallow learning
   1969, Friedrich Nietzsche, Twilight of the Idols:
   Women are considered deep - why? Because one can never discover any bottom to them. Women are not even shallow.
6. (obsolete) Not deep in tone.
7. (tennis) Not far forward, close to the net.
   Rosol spurned the chance to finish off a shallow second serve by spooning into the net, and a wild forehand took the set to 5-4, with the native of Prerov required to hold his serve for victory. June 28, 2012, Jamie Jackson, “Wimbledon 2012: Lukas Rosol shocked by miracle win over Rafael Nadal”, in the Guardian
8. (angles) Not steep; close to horizontal.
   a shallow climb; a shallow descent; a shallow bank angle
   The planes then flew side by side with motors wide open in a very shallow climb.... July 24, 1922, Aviation Magazine
   If they [the Apollo astronauts] come in too steeply, they will be crushed in the Earth’s atmosphere. If they come in too shallow, they will skip out and go into Earth orbit and not be able to return. December 20, 1968, CBS Evening News

noun

1. A shallow portion of an otherwise deep body of water.
   The ship ran aground in an unexpected shallow.
   It happened that, as I was watching some of the little people bathing in a shallow, one of them was seized with cramp and began drifting downstream. 1895, H. G. Wells, The Time Machine
2. A fish, the rudd.
3. (historical) A costermonger's barrow.
   You might have gone there quite as easily, and enjoyed yourself much more, had your mode of conveyance been the railway, or a hansom, or even a costermonger's shallow. 1871, Belgravia, volume 14, page 213

verb

1. (transitive, intransitive) To make or become less deep.
   The shallowing of Cenozoic age-frequency curves from tropics to poles thus appears to reflect the decreasing probability for genera to reach and remain established in progressively higher latitudes ( 9 ). February 6, 2009, Andrew Z. Krug et al., “Signature of the End-Cretaceous Mass Extinction in the Modern Biota”, in Science, volume 323, number 5915, →DOI, pages 767–771