nocturnal

[nok-tur-nl]

adjective

1. of or relating to the night (diurnal ).

2. done, occurring, or coming at night.

   nocturnal visit.

   Synonyms: nighttime

3. active at night (diurnal ).

   nocturnal animals.

4. opening by night and closing by day, as certain flowers (diurnal ).

noun

1. Archaic.,  an astrolabe for telling time at night or for determining latitude by the position of certain stars in reference to Polaris.

nocturnal

/ nɒkˈtɜːnəl /

adjective

1. of, used during, occurring in, or relating to the night

2. (of animals) active at night

3. (of plants) having flowers that open at night and close by day

nocturnal

1. Occurring at night.

2. Most active at night. Many animals, such as owls and bats, are nocturnal.

3. Having flowers that open during the night and close at daylight. Nocturnal plants are often pollinated by moths.

4. Compare diurnal

Other Word Forms

• nocturnality noun
• nocturnally adverb
• nonnocturnal adjective
• nonnocturnally adverb
• seminocturnal adjective
• unnocturnal adjective
• unnocturnally adverb

Word History and Origins

Origin of nocturnal¹

From the Late Latin word nocturnālis, dating back to 1475–85. See nocturn, -al ¹

Word History and Origins

Origin of nocturnal¹

C15: from Late Latin nocturnālis, from Latin nox night

Example Sentences

When dinosaurs reigned, the small creatures evolving into mammals survived by becoming nocturnal, keeping out of sight.

Read more on The Wall Street Journal

Understanding its behavior and ecology is now vital for developing conservation and management strategies that can help protect one of Europe's most extraordinary nocturnal predators.

Read more on Science Daily

These biologging devices tracked their every move and captured the sounds around them, offering a detailed view of their nocturnal behavior.

Read more on Science Daily

Even the nocturnal creatures crawled out from their burrows, into daylight, to join the celebration.

Read more on Literature

A new study published in the British Ecological Society's journal People & Nature has found that these historic buildings are providing vital homes for the nocturnal animals.

Read more on BBC

Related Words

• nightly 
• nighttime