| Tristan's love | 18 |
| Tristan's tryster | 21 |
| King Mark's bride | 21 |
| Tristan's lady | 18 |
| Wagnerian soprano | 17 |
| Wagner princess | 15 |
| Tryster with Tristan | 20 |
| Tristan's lover | 19 |
| Princess in a Wagner opera | 26 |
| Legendary Irish princess | 24 |
| Wagner's "Tristan und ___" | 40 |
| Wagner opera heroine | 20 |
| Tristan's secret love | 25 |
| Tristan's partner | 21 |
| Tristan's companion | 23 |
| She had a tryst with Tristan | 28 |
| Lover of Tristan | 16 |
| Flagstad role | 13 |
| "Tristan und ___" | 27 |
| Wagnerian royal who drinks a love potion | 40 |
| Wagnerian lady | 14 |
| Wagner title character | 22 |
| Wagner soprano role | 19 |
| Tristram's wife | 19 |
| Tristan's tryst partner | 27 |
| Tristan's operatic lover | 28 |
| Tristam's love | 18 |
| Title heroine of a Wagner opera | 31 |
| Singer of the Wagner aria "Liebestod" | 47 |
| Singer of "Liebestod" | 31 |
| She trysted with Tristan | 24 |
| She sings "Liebestod" | 31 |
| Role for Flagstad | 17 |
| Role Flagstad often had | 23 |
| Lover of Arthurian legend | 25 |
| King Mark's wife | 20 |
| Irish princess of legend | 24 |
| Irish princess | 14 |
| Heroine of Arthurian romance | 28 |
| Figure of Arthurian romance | 27 |
| Beloved of Tristram | 19 |
| Beloved of Tristan | 18 |
| Arthurian adulteress | 20 |
| A role for Flagstad | 19 |
| "Liebestod" singer | 28 |
| 'Tristan and --' | 24 |
| Chemical relative | 17 |
| Compound with multiple forms | 28 |
| Compound similar to another | 27 |
| Chemical cousin | 15 |
| Glucose, to fructose | 20 |
| Beta carotene, for one | 22 |
| Chemical "twin" | 25 |
| Related compound | 16 |
| One of chemically related compounds | 35 |
| Fraternal twin, in chemistry | 28 |
| Ethanol, in relation to dimethyl ether | 38 |
| Cousin of a compound | 20 |
| Compound resembling another | 27 |
| Compound related to another | 27 |
| Chemistry test topic | 20 |
| Chemistry exam topic, perhaps | 29 |
| Certain nuclide | 15 |
| Variant compound | 16 |
| Similar compound | 16 |
| Same compound with a different arrangement of atoms | 51 |
| Radioactive nucleus | 19 |
| Phenanthrene, to anthracene | 27 |
| Pentane, e.g. | 13 |
| Nuclear compound | 16 |
| Neopentane, to pentane | 22 |
| Fulminic acid, to cyanic acid | 29 |
| Ethanol, to dimethyl ether | 26 |
| Diethyl ether, to butanol | 25 |
| Compound's close relative | 29 |
| Compound variation | 18 |
| Compound variant | 16 |
| Compound related to another compound | 36 |
| Chemically related compound | 27 |
| Chemical compound resembling another one | 40 |
| Chemical "anagram" | 28 |
| Butylene e.g. | 14 |
| Beta-carotene, e.g. | 19 |
| Alanine or dioxin | 17 |
| Glucose and fructose, e.g. | 26 |
| Some similar chemical compounds | 31 |
| Variants of a compound | 22 |
| Paired nuclides | 15 |
| Ethanol and dimethyl ether, e.g. | 32 |
| Compounds used by nuclear physicists | 36 |
| Compounds relating with others | 30 |
| Compound variants | 17 |
| Chemically similar substances | 29 |
| Chemically related compounds | 28 |
| Chemical cousins | 16 |
| Chemical compounds resembling others | 36 |
| Chemical analogues | 18 |
| Certain similar chemical compounds | 34 |
| Butane and methylpropane | 24 |
| Beta carotene and the like | 26 |