APL

noun

"apl" is a 3-letter English headword indexed on PlainSpell.

The verdict

“APL” sits in 20 confusable pairs (corpus #48,593) as a noun. The look-alike neighbours are the real trap.

#48,593
frequency rank, English
3,931
“A” headwords
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of acute promyelocytic leukemia.

Corpus desk

Index EN-apl · APL · English

APL · rank #48,593 · 0 variants · 20 confusables

  • FREQ-MID #48,593
  • LEN-MID 3 letters
  • VOW-1 1 vowel
  • CONFUS-HIGH 20 pairs
  • VAR-0 0 variants
  • BOOK-MID 3,931
  • PHOTO-FINISH antipsychotic

Nearest frequency peer: antipsychotic (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Frequency neighbours of confusable “APL”

Peers at similar corpus weight, separate from look-alike pairs below

corpus weight

What this shows Bars place “APL” against nearest ranked English headwords, not a reprint of the confusable-pair desk.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

APL vs as
0% similar
APL vs at
0% similar
APL vs aw
0% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for APL
PropertyValue
HeadwordAPL
LanguageEnglish
Part of speechNoun
Letters3
Frequency rank#48,593
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Corpus rank beside confusables of “APL”

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).APLlands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Same rarity band neighbours include “antipsychotic” (#48,592), “apogee” (#48,594), “ANOVA” (#48,591). Among 3,931 “A” headwords, “APL” is #48,593. Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for APL is neighbouring look-alikes ("as", "at", …), not just typos; it is anoun. Frequency #48,593 among 3,931 “A” headwords. 2 recorded senses keep meaning in play.

We couldn't generate a plausible misspelling set for APL, typically a sign the spelling maps closely to how the word sounds. It also participates in 20 confusable-pair relationships, "as", "at", "aw", and more, where similar look or sound leads writers to substitute one word for another in context.

Etymologically, the entry records: (computer language): From the book A Programming Language (1962). The correct English form is APL, spelled A-P-L.

Definition

  1. 1
    Initialism of acute promyelocytic leukemia.
  2. 2
    Initialism of assistant patrol leader.

Recorded use

Wiktionary example

These source excerpts show how APL appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The disease that stood at the pivotal crossroads of oncology was yet another rare variant of leukemia called acute promyelocytic leukemia—APL.

Etymology

(computer language): From the book A Programming Language (1962).

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "APL"?
"APL" is spelled A-P-L.
What does "APL" mean?
As a noun, "APL" means: Initialism of acute promyelocytic leukemia.
What words are commonly confused with "APL"?
"APL" is commonly confused with "as", "at", "aw". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
What is the origin of the word "APL"?
(computer language): From the book A Programming Language (1962). See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "APL", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list