Bounty Ended with 50 reputation awarded by ghosts_in_the_code
3 -2 bytes
source | link

Perl, 47 4343 41 + 1 = 4442 bytes

-4 bytes thanks to @Sunny Pun. -2 bytes thanks to @Brad Gilbert b2gills and @Downgoat

Run with the -n flag.

say!!/^(s(in?)?|co?|t(an?)?|ln?|log?|e)+$/i

I'm not sure this regexIt can definitely be golfed any furtherfuther, but I'll keep trying thingsin the spirit of competition, I'm leaving the mostly-original regex I came up with at the beginning. Returns nothing if true, 1 if false.

Try it online!Try it online!

I downloaded a dictionary file, and the longest word I found was 11 letters -- tattletales

Perl, 47 43 + 1 = 44 bytes

-4 bytes thanks to @Sunny Pun

Run with the -n flag.

say!!/^(s(in?)?|co?|t(an?)?|ln?|log?|e)+$/i

I'm not sure this regex can be golfed any further, but I'll keep trying things.

Try it online!

I downloaded a dictionary file, and the longest word I found was 11 letters -- tattletales

Perl, 47 43 41 + 1 = 42 bytes

-4 bytes thanks to @Sunny Pun. -2 bytes thanks to @Brad Gilbert b2gills and @Downgoat

Run with the -n flag.

say!/^(s(in?)?|co?|t(an?)?|ln?|log?|e)+$/

It can definitely be golfed futher, but in the spirit of competition, I'm leaving the mostly-original regex I came up with at the beginning. Returns nothing if true, 1 if false.

Try it online!

I downloaded a dictionary file, and the longest word I found was 11 letters -- tattletales

2 -4 bytes thanks to @Sunny Pun
source | link

Perl, 4747 43 + 1 = 4844 bytes

-4 bytes thanks to @Sunny Pun

Run with the -n flag.

say!!/^(s(in?)?|c(os?)|co?|t(an?)?|ln?|log?|e)+$/i

I'm not sure this regex can be golfed any further, but I'll keep trying things.

Try it online!Try it online!

I downloaded a dictionary file, and the longest word I found was 11 letters -- tattletales

Perl, 47 + 1 = 48 bytes

Run with the -n flag.

say!!/^(s(in?)?|c(os?)?|t(an?)?|ln?|log?|e)+$/i

I'm not sure this regex can be golfed any further, but I'll keep trying things.

Try it online!

I downloaded a dictionary file, and the longest word I found was 11 letters -- tattletales

Perl, 47 43 + 1 = 44 bytes

-4 bytes thanks to @Sunny Pun

Run with the -n flag.

say!!/^(s(in?)?|co?|t(an?)?|ln?|log?|e)+$/i

I'm not sure this regex can be golfed any further, but I'll keep trying things.

Try it online!

I downloaded a dictionary file, and the longest word I found was 11 letters -- tattletales

1
source | link

Perl, 47 + 1 = 48 bytes

Run with the -n flag.

say!!/^(s(in?)?|c(os?)?|t(an?)?|ln?|log?|e)+$/i

I'm not sure this regex can be golfed any further, but I'll keep trying things.

Try it online!

I downloaded a dictionary file, and the longest word I found was 11 letters -- tattletales