What does 一途 mean as a suffix?

Question

I occasionally run across [一途]{いちず} used as a suffix in a couple different words, often forming a 四字熟語. Examples include 学問一途, 純真一途, 憧憬一途, 正直一途, 誠実一途 and so on. However, I'm having trouble finding dictionary definitions that address this usage as a suffix.

I get that 一途 has the general meaning of wholehearted, single-minded, earnest devotion to a cause, but how should we parse new 四字熟語 words when it's used as a suffix? Is there a better rule or pattern we can try to apply, or do we just need to learn the meaning of each word individually?

At least to me, the meanings seem to fall into at least three categories:

1. Single-minded devotion to the cause preceding 一途

• 学問一途: Devoted to one's studies
• 仕事一途: Devoted to one's work

2. An extremely high degree of the quality preceding 一途

• 純真一途: Incredibly pure and innocent
• 正直一途 / 誠実一途: Incredibly honest and sincere

3. Being or having the quality preceding 一途 in an 一途 way

• 憧憬一途: Single-minded/devoted yearning/admiration (not sure on this meaning)

Is there a better way to think about this?

Answer 1

None of your examples is a widely-recognized idiomatic yoji-jukugo, and I haven't regarded 一途 as a suffix. Of course, that is not to say I cannot grasp the meaning of those phrases.

Something like 純真一途 is simply two similar two-kanji words put together to form a (nonidiomatic) yoji-jukugo. Similar widely-known examples include 純真無垢, 美辞麗句 and 厚顔無恥. 学問一途 is a contracted version of 学問に一途; に has been dropped to form a yoji-jukugo, and something like this is very common in titles and headlines. All the examples under 1 and 2 can be explained within the general nature of yoji-jukugo. I don't believe there is anything unique about 一途.

憧憬一途 was a bit puzzling at first sight, but this is a unique ateji skill name specific to this character. This can be understood as two words related to his personality put together. It could have been 一途憧憬.