Fenugreek is an old Thai herb that I just discovered closer-by than I'd realized. I have known and used fenugreek in my Indian cooking for years without appreciating that it was the same as 'loog sud'. I'd also always associated the spice with old Thai clothing care more than cooking, so I couldn't put the two together.
In the palace, where noble girls learned the arts of being a proper Thai woman, caring and scenting clothes was part of the work. Clothes were boiled with fenugreek, other herbs and fragrant flowers, dipped in wax, dried, scraped, pleated and folded into the desired shapes. Fenugreek gives out cloudy slime when boiled or heated with hot water which binds into the fabric when dried, similar to starch that we use today to harden and keep our clothes smooth. Each household/palace had their own formula for a distinct scent. It was said that the beautiful scent from a palace lady's clothes remained long after she had left.
Researchers in Thailand credit fenugreek with lowering blood sugar and increasing milk production in nursing mothers. In Thailand, fenugreek is available at traditional pharmacies and spice stores.
When you smell a whiff of fenugreek, if you think that you're smelling curry powder, you're right. It's part of curry powder. Outside of Thailand, whole fenugreek seeds are available at Indian grocery stores and called "methi," powder form is available at health food stores. When making curry powder, I recommend getting whole seeds from Indian stores.