| BOOLEAN | One old lab developed a logical system of counting (7) |
| RAMEAN | Artist with design following a logical system |
| DECIMAL | System of counting mail revised a month before (7) |
| ORGANON | Logical system needed by Billy Preston in order to play? (7) |
| PLACEBO | OPEC lab developed experimental drug? (7) |
| BALLAST | Lab developed ultimate heavy material (7) |
| EXIGUUS | Dionysius -; canonist who devised the Anno Domini system in 525 as a means of counting years (7) |
| BOOLEANALGEBRA | Show disapproval of a general lab changing logical system (7,7) |
| CRORE | In the Indian system of counting or numbering, a word of Sanskrit origin used to represent 10 million people, rupees, units etc; or, 100 lakhs (5) |
| DUODECIMAL | As a system of counting, doctor aided locum (10) |
| NUMBERING | ... to anaesthetising without hesitation or any system of counting (9) |
| ALGORISM | The Arabic or decimal system of counting (8) |
| ENTAILS | Has as a logical consequence (7) |
| ORDERED | Directed to be put in a logical arrangement (7) |
| DEDUCED | Drew as a logical conclusion (7) |
| NATURAL | A logical name to give to mountains (7) |
| DIGIT | Word for 1/12 of the diameter of the Sun or the Moon; a numeral; any one of the fingers, so called for the practice of counting on said pinkies, pointers or "Onkaparingas"; or, a finger-breadth (5) |
| PREMISE | Start of a logical argument |
| ANTIBACTERIAL | Like a drug that's intricate a lab developed (13) |
| SALADBOWL | Item of tableware found when old lab was demolished (5,4) |
