名詞 modal:

1. an auxiliary verb (such as `can' or `will') that is used to express modality
   同義詞：modal auxiliary verb, modal auxiliary

形容詞 modal:

1. relating to or constituting the most frequent value in a distribution
   同義詞：average
2. of or relating to a musical mode; especially written in an ecclesiastical mode
3. relating to or expressing the mood of a verb

mod.al

adj.（形容詞）
Of, relating to, or characteristic of a mode.
方式上的：方式的，關(guān)于方式的，或以方式為特征的
Grammar Of, relating to, or expressing the mood of a verb.
【語法】 語氣的：屬于，有關(guān)或表達(dá)一個(gè)動(dòng)詞的語氣的
Music Of, relating to, characteristic of, or composed in any of the modes typical of medieval church music.
【音樂】 屬于，關(guān)于中世紀(jì)的教會(huì)音樂的，以其為特征的，或由這種調(diào)式譜寫的
Philosophy Of or relating to mode without referring to substance.
【哲學(xué)】 模式的：屬于或關(guān)于樣式卻不涉及本質(zhì)的
Logic Expressing or characterized by modality.
【邏輯學(xué)】 程式的：用程式表示的或以其為特征的
Statistics Of or relating to a statistical mode or modes.
【統(tǒng)計(jì)學(xué)】 眾數(shù)的：屬于或關(guān)于統(tǒng)計(jì)眾數(shù)的

來源：
Medieval Latin mod3lis
中世紀(jì)拉丁語 mod3lis
from Latin modus [measure] * see med-
源自 拉丁語 modus [測(cè)量] *參見 med-

【引伸】
mo.dally
adv.（副詞）