Question: Which two Ancient Greek words form the root of the word pathology?
About the article "Pathology", section "Abstract".

Candidate passages:
The citation form shown is the form most commonly shown in dictionaries, but this form is often unrepresentative of the word as used to form a compound word, hence the root form is also shown.
In the case of verbs, the citation form is often by convention the first person singular, present indicative, (cf Latin), for instance (phagō), "I eat", rather than the infinitive ("to eat").
The Greek forms are generally in their true root form; i.e., a noun or verb derived from an earlier form will appear under the earlier form.
The "classical" transliteration as described above is used for both the Citation form and the Root form.
Greek entries are in alphabetical order according to the Greek alphabet, English entries by the Roman alphabet.
The Greek words are shown in polytonic orthography, in other words showing the breathings and the fuller range of accents, as used in Ancient Greek and in Modern Greek for those who do not accept the 1982 "monotonic reform".
Note that alpha privatives are addressed under the heading of the positive form of the word whenever possible.ab 
The word "Radical" is derived from the ancient Greek word "radix" meaning root. 
Crasis (English pronunciation, ) is a type of contraction in which two vowels or diphthongs merge into one new vowel or diphthong — making one word out of two.
Crasis occurs in Portuguese and Arabic as well as in Ancient Greek, where it was first described.
In some cases, as in the French examples below, crasis involves the grammaticalization of two individual lexical items into one, but in other cases, as in the Greek examples, crasis is the orthographic representation of the encliticization and vowel reduction of one grammatical form with another.
The difference between the two is that the Greek examples involve two grammatical words and a single phonological word and the French examples involve a single phonological word and grammatical word. 
The name derives from the Italian word for seashell ("conchiglia").
The Italian word "conchiglie", and the English word "conch", share the same Greek root in the form of "konkhe", which means "shell". 
During the Migration Period, the Germanic languages' names for the cardinal directions entered the Romance languages, where they replaced the Latin names "borealis" (or "septentrionalis") with north, "australis" (or "meridionalis") with south, "occidentalis" with west and "orientalis" with east.
It is possible that some northern people used the Germanic names for the intermediate directions.
Medieval Scandinavian orientation would thus have involved a 45 degree rotation of cardinal directions.
"north" (Proto-Germanic "*norþ-") from the proto-Indo-European *"nórto-s" 'submerged' from the root *"ner-" 'left, below, to the left of the rising sun' whence comes the Ancient Greek name "Nereus".
"east" ("*aus-t-") from the word for dawn.
The proto-Indo-European form is *"austo-s" from the root is *"aues"- 'shine (red)'.
See "Ēostre".
"south" ("*sunþ-"), derived from proto-Indo-European *"sú-n-to-s" from the root *"seu"- 'seethe, boil'.
Cognate with this root is the word "Sun", thus "the region of the Sun."
"west" ("*wes-t-") from a word for "evening."
The proto-Indo-European form is *"uestos" from the root *ues- 'shine (red)', itself a form of *"aues"-.
Cognate with the root are the Latin words "vesper" and "Vesta" and the Ancient Greek "Hestia", "Hesperus" and "Hesperides".