From what I read, 厚い is used when something is thick or abundant and 篤い is used when describing a serious illness. But what confuses me is that in a dictionary (Tagaini Jisho) both of these are in the same entry, is it because the kanji can be interchangeable? Is 篤い commonly used? And which kanji would be used for the second definition hospitable?
The entry: 厚い Alternate writings: 篤い (あつい)
- Thick, deep, heavy. [ 厚い (あつい) ]
- Kind, cordial, hospitable, warm, faithful.
- Serious (of an illness). [ 篤い (あつい) ]
- Abundant. [ 厚い (あつい) ]