Does the chengyu 话不投机 (huà bù tóu jī) mean "uncongenial speech"? I'm looking at creating a CC-EDICT entry for 话不投机 (huà bù tóu jī).  This will need to go through their review process:

All submitted entries will be queued for reviewing by the CC-CEDICT editors team.

(See examples in their Change Log to see the evidence required for &quot;submitted&quot; entries.)
I've never done this before, but I thought I'd give it a try.  Here's a start:

Traditional: 話不投機
Simplified: 话不投机
Pinyin: hua4 bu4 tou2 ji1
English: /???/

My best attempt at an English translation is &quot;uncongenial speech&quot;, where 不 = &quot;not&quot;, 投机 = &quot;congenial&quot;, and 话 = &quot;speech&quot;.
Question: Does the chengyu 话不投机 mean &quot;uncongenial speech&quot;?
Some online examples (with my partial translations):

想有段亲密恋情，却发现话不投机，好好聊天才是捷径[src]
Want a period of time of intimate romance, but encountered 话不投机, nicely chatting is the only shortcut
话不投机比不相爱更可怕[src]
话不投机 is scarier than unrequited love
婚姻生活许多话不投机，不愿意曲意逢迎那就掩耳不听[src]
Married life [has] lots of 话不投机, [be] unwilling to bow down to everything [and] refuse to listen

These all seem consistent with 话不投机 = &quot;uncongenial speech&quot;.  It's surely also related to the CC-CEDIT entry:

话不投机半句多
when words get sour, adding words is useless (idiom)

This translation is in Tales of Herding Gods (牧神记).  This is consistent with 话不投机 = &quot;uncongenial speech&quot;.

Wayne Cheah's comment let me to this Song Dynasty poem which contains the longer version:

酒逢知己千杯少，话不投机半句多。

CC-EDICT also has an entry for the first part:

酒逢知己千杯少
a thousand cups of wine is not too much when best friends meet (idiom); when you're with close friends, you can let your hair down


Update: What I currently have in mind now (which seems more accurate):

/unagreeable or unenjoyable talk (idiom)/when words go sour/

It looks like it'd be worth updating 话不投机半句多 to:

/when words go sour, adding words is useless (idiom)/fig. in an unagreeable conversation, half a sentence is too much/


Update:  It was added/amended here with major changes:


話不投機半句多 话不投机半句多 [hua4 bu4 tou2 ji1 ban4 ju4 duo1] /when views are irreconcilable, it's a waste of breath to continue discussion (idiom)/
話不投機 话不投机 [hua4 bu4 tou2 ji1] /the conversation is disagreeable (idiom)/
話不投機 means you don't share similar interesting or thoughts to chat with people or people don't like what you talk about, think it is not interesting.

Regardless the sentences of example you give is true or not, I just consider the semantic since I am not psychological professional.

发现话不投机，好好聊天才是捷径 show that people have the property of 话不投机 so on the latter part of sentence it encourage people to 好好聊天.

话不投机比不相爱更可怕 shows that 话不投机 is more horror then 不相爱.

许多话不投机 shows that the couple have a lot of different belief.

话不投机半句多 shows that you feel that 半句 is enough if the chat is 话不投机(you feel 半句 is a large amount since it is undesirable).

.