Written by Colin Lu
As hinted by the styling of the two separated sets of clues and the title, the answers to the clues need to be paired up in some way.
As the solver answers some of the clues, they'll start to see that the answers from the right side clues contain the answers to the left side clues as substrings.
In each case there are at least two letters on either side of the substring word, which can help with pairing them up. Furthermore, the enumerations of the words on the right side are given.
There is only one way to pair up all of the words in this way. The left side words are sorted alphabetically, while the words on the right are not, which suggests that we should use the ordering given by the right side. The numbers given with the words on the left side are in many cases longer than the left side words, which suggests that we should use them to index into the right side words:
|Left clue||Right clue||Left word||Right word||Index||Letter to extract|
|__zone||Tender or romantic emotion||TIME||SENTIMENT||6||M|
|Complete||Country in Southeast Asia||DONE||INDONESIA||6||E|
|Unit of speed||Benjamins||KNOT||BANKNOTES||6||O|
|Sad||Someone with a lot of property||DOWN||LANDOWNER||6||W|
|Longer than a yard||Settings of many horror movie scenes||METER||CEMETERIES||5||T|
|MOBA game developer||National pride||RIOT||PATRIOTISM||5||I|
|Most frequent||Type of art or architecture||MODE||POSTMODERN||5||M|
|Word class||Commonly referred to||VERB||PROVERBIAL||5||E|
|Technical standard or skirt||Water intaking machine that eases dry skin||MIDI||HUMIDIFIER||5||D|
|Undecorated||Mysterious, despite investigation||PLAIN||UNEXPLAINED||3||E|
|Sage, for instance||Computer component||HERB||MOTHERBOARD||3||T|
|Spanish greeting||Educational grant||HOLA||SCHOLARSHIP||3||H|
|Fraction of an SI base unit||Scripting or brainwashing||GRAM||PROGRAMMING||3||O|
|Prescription unit||A narrow tube||PILL||CAPILLARY||4||I|
|International alliance||Oriental area of a city||NATO||CHINATOWN||4||N|
|State also known as "the zone"||Famous ship of the Pilgrims||FLOW||MAYFLOWER||4||F|
|Part in a movie||Type of jelly or oil||ROLE||PETROLEUM||4||R|
|Helpful device for shopping||Famous Beatle||CART||MCCARTNEY||4||A|
|Review symbol||Product used to make non-Newtonian fluid||STAR||CORNSTARCH||5||S|
|Nice way to describe something small?||Contest participant||PETIT||COMPETITOR||5||E|
|Opposite of dark||Pleasing or charming||LIGHT||DELIGHTFUL||5||G|
|University period||Wealthfront alternative||TERM||BETTERMENT||5||E|
|Currency denomination smaller than a dollar||Delta accumulations||DIME||SEDIMENTS||1||S|
|All according to __||Clear, level space, often by the seaside||PLAN||ESPLANADE||1||E|
|Temporary accomodation||Concern of HR departments||TENT||RETENTION||1||R|
|Test version||Unspeakable villain||DEMO||VOLDEMORT||1||V|
|Pirate's storage container||Large musical group||CHEST||ORCHESTRA||1||O|
Solvers will also notice that for each uninterrupted string of right side clues with the same enumeration, the corresponding words from the left side clues have the same index, which further helps with matching them up.
Reading the extracted letters gives the words MEOW, TIMED, ETHOS, INFRA, SEGUE, and SERVO, with the changes in enumeration length also cluing the word boundaries.
At this point, solvers may notice that all of these words fit into a longer word in the same way as in the first step of the puzzle, with the enumeration given by the shared enumeration of the right clue answers. While there are no clues for the longer words this time, the container words are all common words, and all of them are the only possible containing words.
The left clue answers giving each of the words above also all have the same index number, so we use this number again, once again to index into the longer words:
|Word||Container||Index||Word length||Letter to extract|
This gives the answer, WIENER.
This puzzle was inspired by noticing some of these crazy pairs of words with no etymological connection, one of which contains the other as a substring. Perhaps the most famous of these is the pair (MEOW, HOMEOWNER), which was used deliberately here to help clue solvers in to the last step. Of course, it turns out there are a large number of such pairs, as I discovered while doing research for this puzzle. The best of these were saved for the last step.
The title somewhat clues what to do in the puzzle, while also being a "container word" itself, containing UNIT, which can be thought of as a synonym for WORD.