What is the name for confusables of similar meanings?

Words which learners (and also native speakers) get confused by are simply called "confusing verbs". There may be a linguistic, more technical term that describes this aspect but I'm not aware of one.

Confusing words–or verbs–are notorious for even tripping up native speakers

For example

• advise (verb) vs advice (noun)
  "Advise" vs. "advice"

• effect vs affect
  "Effect" vs. "Affect"

• bring vs take
  "Bring" versus "take"

• borrow vs lend
  Word to describes the money that you lend to somebody?

• compliment vs complement
  i) Mnemonic for "complement / compliment"
  ii)"Complimentary" vs "complementary"

• lay vs lie
  What is the difference between "lay" and "lie"?

• do vs make vs take
  admittedly in this instance knowing which verb to use is more confusing for non-native than native speakers.
  i) What is the difference between the verbs "make and "do"?
  ii) What is the difference between 'make an experiment' and 'do an experiment'?
  iii) What is the difference between 'make decision' and 'take decision'?
  iv) Make/take a photograph?

• practice vs practise
  i) "Practise" vs. "practice" ii) Can Practice (verb) and Practise (verb) indicate two different meanings?

• rise vs raise
  i) What is the difference between "raise" and "rise"?
  ii) "Pay rise" vs "pay raise"

• say vs tell
  "Told" vs. "said to" somebody

Other types of confusing words are homophones which are two or more words whose meanings and spellings are different but are pronounced in the same way. Examples:

• ate vs eight
• led vs lead (the metal)
• site vs sight
• flower vs flour
• they're vs their vs there
• to vs too vs two

Words that have the same spelling and pronunciation but different meanings are called homonyms

e.g
the tree's bark (outer layer) vs most dogs bark (sound)

The stalk of a plant (part of a plant) vs to stalk someone (verb)

Waiter there's a fly in my soup (the insect) vs Come fly away with me (verb)

The term confusables includes words with similar but non-identical meanings like imply/infer and less/fewer. A term that applies principally to similar or related meanings is

near-synonym

(linguistics) A term whose meaning is similar, but not identical, to that of another term. Wiktionary

A word that has almost the same meaning as another word:

The words "hungry" and "peckish" are near-synonyms.

Near synonyms are more common than perfect synonyms.

Near-synonyms may be regarded as equivalent for some purposes, but not others. Cambridge

case. This multifaceted word is often a sign of verbal inflation, especially in its uses as a near-synonym of situation.
...
include; comprise. The basic difference between these near-synonyms is that include implies nonexclusivity..., while comprise implies exclusivity... Garner; The Chicago Guide to Grammar, Usage and Punctuation

A list of commonly used near-synonyms

Here are some examples of commonly used near-synonyms for legal concepts used in legal documents. There are subtle differences in meaning or usage between them.

Assign...transfer
Breach...infringement
Clause...article
Contract...agreement
... Rupert Haigh; Legal English p.81

confusable (noun)

Two or more words or ideas that can easily be confused

confusables such as ‘principle’ and ‘principal’ Oxford Advanced Learner's

(The above definition of the singular as "two or more ..." bothers me.)

A word or phrase that is easily confused with another in meaning or usage such as mitigate which is often confused with militate. New Oxford American Dictionary

A word or phrase that is easily confused with another Wiktionary

(I do not see the noun in the OED.)

A related term is partial synonym

See What is the difference between partial and total synonyms?

Synonymy, as we have seen, is defined where two lexemes are mutually hyponymous, in other words where their extensions (and senses) are required to be identical, as shown in (61)
....
Unfortunately this definition does not allow for partial synonymy, since extensions in the theory are discrete, i.e. there are no fuzzy edges where, for example there may be things that are almost pullovers but that are not a sweater. Since, as we have noted, full synonymy is rarely, if ever, attested, this makes the definition in (61) less useful than it might be. Ronnie Cann; Formal Semantics, p. 220