A click as a noun is a small, sharp sound. It is usually metallic, although it can be made against other hard things. This is the common meaning I found and it is usually accompanied by an adjective like sharp, faint, or loud. As a verb it is usually to make the clicking sound. However, there are also other meanings. The OED listed that it could mean to become pregnant or to get killed.

When you meet someone you immediately get along with it is said that the two of you “click.” I found this usage by looking for he|she|they|we|I [click]and found it in 2009, number 79. However, most uses found were about someone clicking something.

Click overall has shown a steady increase in usage. Noun and verb follow those results.

Collocates between 1880-1900 and 1980-2000.

Nearby Nouns:

1880-1900 1980-2000

1	INSTRUMENT	1	MOUSE
2	HAMMERS	2	PHONE
3	BILLIARD	3	BUTTON
4	HOOFS	4	MACHINE
5	SNOWSHOES	5	TAB
6	TELEGRAPH	6	SCREEN
7	PISTOLS	7	LIGHT
8	BALL	8	RADIO
9	GUN-LOCK	9	COMPUTER
10	INSTANT	10	LINE

It used to be strictly the sound that was used. The balls clicked together or the hammers clicked. But this list shows that today we click a mouse or click on something on the computer.

Nearby Verbs:

1880-1900 1980-2000

1	UTTERED	1	'S
2	FELL	2	GET
3	MET	3	HAS
4	SOUNDED	4	GO
5	CAME	5	HAVE
6	STOOD	6	'RE
7	WENT	7	DO
8	HEARD	8	OPEN
9	CLOSED	9	HANGS
10	FOLLOWED	10	'D

Again, the sound is used at the beginning. They heard a click, they came clicking. Now we "go click" something although we still hear the click of the phone as we hang up.

Adjectives:

1880-1900 1980-2000

1	SHARP	1	OPEN
2	LITTLE	2	SHUT
3	FAINT	3	DEAD
		4	AUDIBLE
		5	NEW
		6	METALLIC
		7	ANSWERING
		8	OTHER
		9	REMOTE
		10	SATISFYING

Click wasn’t used much in the first century but usage hasn’t changed much otherwise. From 1880 to 1900 the adjectives all relate to sound. In 1980 to 2000 there is still sound, but there is also “click open” or “click shut”. I was curious about dead, and found that all uses there were referring to the telephone clicking dead.

Cowardice

Gutless: originated from the term guts to mean someone who has no guts or courage. Ayto lists that this slang came into use in 1900, but COHA has its first instance in 1945. Gutless is used in its literal meaning a couple times in COHA (including 1941) and a book uses it as a proper noun in 1995, but overall it has had a slow increase in usage since then.

Yellow bellied: Yellow bell* has one instance in 1954. For [yellow-bell*] usage Ayto says it first occurred in 1924 and COHA has use in fiction in 1912 with its next usage in 1924. Usage is almost equally mixed with its literal meaning.

Chicken is the name of an animal and is thus used a lot. However, there are some early cases that are phrased much like we would use them today as the figurative slang. It is used in reference to the way a chicken would act, that is cowardly. Ayto has 1933 for the adjectival use of chicken. COHA has 1815. For [pp*] [be] chicken the first figurative usage is recorded in 1945 with “you’re chicken.” The 1960s use is mostly figurative while other decades are mainly literal.

Milky originated from the use of the word milk as mildness or weakness. Ayto says it first occurred in this sense in 1936. In COHA there are cases of use of milky in a figurative sense from 1811.

Punk out is to lose one’s nerve. COHA has two instances from 1995 and COCA has a few more starting in 1991. Ayto says that its use started in 1920 in the US, but I was unable to find anything else. The earliest use was actually found in 1958 according to the TIME corpus.

Wimp out has the same meaning as punk out except the word wimp suggests a feeble person. Ayto gives its arise in 1981 which all three corpora agree with since the earliest once shows in 1989. It has increased in use, but the numbers are so low it doesn’t give much statistical evidence. COHA COCA TIME

Fraidy-cat [fraidy cat] and scaredy-cat [scaredy cat] are both used rather sporadically. Scaredy-cat was used first in the 1910s, fraidy-cat in the 1940s. Both are mainly used by children.

If you are in a blue funk you are afraid. Ayto gives first usage as 1861. It first shows up in COHA in 1868 and though it does continue, it doesn’t have high numbers.

Funky came from the word funk which in the earlier sense meant fear. Ayto dates this at 1860 and in COHA it shows up in 1861. Afterwards though, while some do maintain this meaning, it also means something strange or bad like a funky smell or taste. Usage has increased but it is likely due to the other meanings.

Another word
Squib was a word for a coward dated 1918 in Australia. I didn’t find any usage for this meaning. It usually means a type of publication.