infant

in-,不，非，-fan,说话，词源同phone,fame.即不能说话的，引申词义婴儿。

infant

infant: [14] Etymologically, an infant is ‘someone who cannot yet speak’. The word comes via Old French enfant from Latin infāns ‘young child’, a noun use of the adjective infāns, originally ‘unable to speak’, which was formed from the negative prefix in- and the present participle of fārī ‘speak’ (source of English fable, fame, fate, etc).

The somewhat improbable derivative infantry [16] comes via French from Italian infanteria; this was based on infante, whose original meaning ‘young person’ had shifted to ‘foot soldier’ (a development distantly reminiscent of the use of British English lads for ‘male members of a group, team, etc’).
=> fable, fame, fate

infant (n.)

late 14c., "child during earliest period of life" (sometimes extended to age 7 and sometimes including a fetus), from Latin infantem (nominative infans) "young child, babe in arms," noun use of adjective meaning "not able to speak," from in- "not, opposite of" (see in- (1)) + fans, present participle of fari "to speak," from PIE root *bha- (2) "to speak, tell, say" (see fame (n.)). As an adjective, 1580s, from the noun.

1. The United States ranks 20th in its infant mortality rate.

美国在婴儿死亡率方面排名第20。

2. There was an infant squalling in the back of the church.

有个婴儿在教堂后部大声啼哭。

3. pioneering work on infant mortality

婴儿死亡率方面的探索性研究工作

4. The operation on the new born infant was a failure.

新生儿的手术失败了.

5. The sole survivor of the crash was an infant.

这次撞车的惟一幸存者是一个婴儿.