Chashinai Railway translations

On the read me for the Chashinai Railway, there are most of the translations for the Japanese announcements, but some are missing. One of them is "kousoku" and the other is "yokusoku." I've figured out what "kousoku" is, it means "high speed" or "fast," but the translation for "yokusoku" is most likely incorrect; "hypodermis."  Can someone please let me know what the translation is for "yokusoku?"

Thanks in advance!

You're thinking of the word (well more technically the Romanji version of the underlying Kanji) in isolation, which is your problem.

For example:
EnpouYokusoku (遠方抑速) translates to 'Distant Suppression' , so in this case would be a distant signal showing the Suppression aspect (e.g. 105km/h , although this may vary between companies. I haven't checked what Chasanai has set for this....)