As nouns the difference between segment and articulus

is that segment is a length of some object while articulus is (zoology) a joint of the cirri of the crinoidea; a joint or segment of an arthropod appendage.

As a verb segment

is to divide into segments or sections.

As nouns the difference between arthropod and articulus

is that arthropod is an invertebrate animal of the phylum arthropoda , characterized by a chitinous exoskeleton and multiple jointed appendages while articulus is (zoology) a joint of the cirri of the crinoidea; a joint or segment of an arthropod appendage.

As a verb propagating

is present participle of propagate.

As an adjective counterpropagating is

describing two beams of light that are propagating in precisely opposite directions through the same medium.

As adjectives the difference between opposite and counterpropagating

is that opposite is located directly across from something else, or from each other while counterpropagating is describing two beams of light that are propagating in precisely opposite directions through the same medium.

As a noun opposite

is something opposite or contrary to another.

As an adverb opposite

is in an opposite position.

As a preposition opposite

is facing, or across from.

As verbs the difference between sing and countersing

is that sing is to produce musical or harmonious sounds with one’s voice while countersing is to sing in response to the song of another.

As a noun sing

is a gathering for the purpose of singing songs.

As a noun response

is (senseid)an answer or reply, or something in the nature of an answer or reply.

As a verb countersing is

(biology|of a bird) to sing in response to the song of another.

Lemmatize is a alternative form of lemmatise.

As verbs the difference between lemmatise and lemmatize

is that lemmatise is an alternative spelling of lemmatize while lemmatize is to convert an inflected form of a lexeme to a lemma.

As verbs the difference between inflect and lemmatize

is that inflect is to cause to curve inwards while lemmatize is (linguistics) to convert an inflected form of a lexeme to a lemma.

As a noun lexeme

is lexeme.

As a verb lemmatize is

(linguistics) to convert an inflected form of a lexeme to a lemma.

As a noun lemma

is lemma (mathematics: proposition used mainly in the proof of some other proposition).

As a verb lemmatize is

(linguistics) to convert an inflected form of a lexeme to a lemma.