doldrums
/ˈdɒldrəmz/
plural noun
the doldrums
1 A state or period of stagnation or depression.
2 An equatorial region of the Atlantic Ocean with calms, sudden storms, and light unpredictable winds.
Origin
Late 18th century (as doldrum ‘dull, sluggish person’): perhaps from dull, on the pattern of tantrums.
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Vague memories sometimes re-appear when we are stuck in the doldrums of our best intentions.