1A large number of fish swimming together.

1. 1.1British informal A large number of people.
   More example sentences

   • ‘a rock star's entrance, first proceeding with his shoal of attendants’
   • ‘In the end I found a whole shoal of them in the sports section.’
   • ‘Before the current intifada began in 2000, shoals of tourists made it difficult to move in these lanes.’
   • ‘The popular take-away and restaurant in Chippenham has been short-listed for the area title of the contest, after shoals of nominations from its customers.’

(of fish) form shoals.

1An area of shallow water, especially as a navigational hazard.

1. 1.1A submerged sandbank visible at low water.
   ‘Of course, an unintended consequence of these jetties was that they created offshore shoals and sandbars that tended to magnify the waves here.’
   More example sentences

   • ‘These offer information about shifting shoals, sandbars and such that can be critical for boaters and productive for fishers.’
   • ‘Oregon's lighthouses were all but inaccessible when they were built in the 19th century, near shoals and sandbars, treacherous offshore rocks and reefs.’
   • ‘With its shoals and proximity to nearby shipping lanes, the Tortugas are a natural ship trap.’
   • ‘For example, your DGPS can conceivably place you within 30 feet of a shoal, but the chart image loaded in the plotter could be one in which that area has not been resurveyed for decades.’
   • ‘Carbonate particles removed from the ‘factory’ zone fed the onshore shoals and beach deposits.’
   • ‘Although the Clyde was broad, until the early 19th century shoals prevented sea-going ships from sailing higher than Port Glasgow some twenty miles downstream.’
   • ‘Where are the navigational hazards such as shoals?’
   • ‘It also addresses the fact that in many of these areas boaters travel near the middle because shoals, stumps, rocks and other hazards often exist near the sides of the channel.’
   • ‘The seabed images were used by the Navy in deciding which areas of shoals and reef needed careful investigations using the ship's echosounder.’
   • ‘However, some of the elementary cycles may have been influenced by intrinsic processes such as local shifting of sand shoals due to wave reworking.’
   • ‘The sand forming these two shoals would ordinarily have been deposited on the East Beach during its eastward drift.’
   • ‘They blamed an uncharted shoal that the vessel must have hit several hours before as the cause of the flooding.’
   • ‘He knows polls and districts and congressional races the way a sea-fisherman knows tides and currents and shoals.’
   • ‘In 1865, the Committee on Roads and Jetties raised funds for the filling and leveling of the shoal near the waterways junction.’
   • ‘It's warm, the spring tide is rising, we're going over a shoal.’
   • ‘He spent ten years working in the coal trade of the east coast of England - with its shoreline of treacherous, shifting shoals, uncharted shallows, and difficult harbours.’
   • ‘The chatter sounds are generally heard in and around sandy bottom areas such as shoals and beaches.’
   • ‘They've navigated their way through narrow channels and around dangerous shoals using the same buoys and other navigational aids.’
   • ‘She remembered driving the Ocean Gypsy onto the shoals.’
   Synonyms

   sandbank, bank, mudbank, bar, sandbar, tombolo, shallow, shelf, sands

   View synonyms
2. 1.2usually shoalsA hidden danger or difficulty.
   ‘he alone could safely guide them through Hollywood's treacherous shoals’
   More example sentences

   • ‘But with deficits rising and businesses anxious for new tax breaks, Congress will first have to navigate the treacherous shoals of domestic politics.’
   • ‘They have been doing so for years, of course, shrewdly navigating the political shoals.’
   • ‘The US is entering uncharted waters, which hide shoals that could cause its economy to sink into a recession and with it stocks and shares plummeting into the deep.’
   • ‘Unfortunately, my spiritual search soon ran aground on the shoals of alcoholism, and would remain marooned there until May, 1993, when I got sober.’
   • ‘In the birthplace of civilization, we have again run aground on the rocky shoals of nationalism, this time augmented by a religious fervor that increases the danger.’
   • ‘In these turbulent waters, the American Navy navigates the political shoals and does what it does best - projects power.’
   • ‘Churches of all sizes and shapes can run aground on this shoal.’

(of water) become shallower.

(of water) shallow.