Modifiers matching perch:

• low,
• artificial,
• elevated,
• nearby,
• off,
• exposed,
• high,
• open,
• inconspicuous,

Simple categories matching open:

• area,
• design,
• burning,
• space,
• position,
• land,
• standard,
• receptacle,
• event,
• bivalve,
• envelope,
• structure,
• water,
• cell,
• woodland,
• country,
• environment,
• activity,
• building,
• code,
• institution,
• flow,
• powerboat,
• office,
• sector,
• program,
• facility,
• fire,
• grain,
• system,
• dish,
• article,
• conduit,
• mollusc,
• container,
• region,
• waterway,
• version,
• establishment,
• group,
• medium,
• field,
• enclosure,
• competition,
• implementation,
• business,
• part,
• shellfish,
• vessel,
• prey,
• struggle,
• light,
• science,
• excavation,
• feature,
• clearing,
• volume,
• unit,
• situation,
• resistance,
• equipment,
• location,
• aquarium,
• fencing,
• seam,
• beam,
• package,
• watercourse,
• flower,
• view,
• grassland,
• vehicle,
• curve,
• basin,
• forum,
• stairway,
• roll,
• place,
• thing,
• construction,
• liquid,
• nut,
• type,
• information,
• air,
• body,
• highway,
• market,
• door,
• image,
• meat,
• ground,
• community,
• territory,
• wound,
• network,
• gesture,
• meeting,
• wall,
• entity,
• object,
• boat,
• conveyance,
• room,
• car,
• stage,
• procedure,
• substance,
• ampoule,
• cover,
• site,
• pattern,
• function,
• appliance,
• application,
• material,
• form,
• issue,
• conflict,
• terrain,
• housing,
• section,
• shelter,
• source,
• item,
• protocol,
• ocean,
• face,
• service,
• workplace,
• patch,
• habitat,
• society,
• specification,
• passage,
• orifice,
• organization,
• box,
• perch,
• file,
• lagoon,
• fixture,
• projection,
• designer,
• document,
• nester,
• sea,
• shape,
• marketplace,
• menu,
• pit,
• knowledge,
• fabric,
• vegetation,
• canopy,
• surface,
• food,
• collocation,
• forest,